[meta-virtualization][RFC][PATCH 1/5] vcontainer-bbmask.inc: add python3-pexpect,-ptyprocess

[meta-virtualization][RFC][PATCH 1/5] vcontainer-bbmask.inc: add python3-pexpect,-ptyprocess

[tim.orling]

From: Tim Orling <tim.orling@konsulko.com>

For multiarch container-yocto-builder, during run-time testing
with the bitbake-setup workflow, it was discovered that we need
python3-pexpect and its dependency python3-ptyprocess.

Remove the layer-wide meta-python BBMASK and allow these
specific recipes.

Once meta-python is allowed, there was an error for
meta-oe/dynamic-layers/meta-python which we do not need for the
above recipes. It can be enabled in the future when needed.

Signed-off-by: Tim Orling <tim.orling@konsulko.com>
---
 conf/distro/include/vcontainer-bbmask.inc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/conf/distro/include/vcontainer-bbmask.inc b/conf/distro/include/vcontainer-bbmask.inc
index 0c9b8b02..0c6a7efc 100644
--- a/conf/distro/include/vcontainer-bbmask.inc
+++ b/conf/distro/include/vcontainer-bbmask.inc
@@ -94,6 +94,8 @@ BBMASK += "meta-openstack/recipes-dbs/postgresql/"
 BBMASK += "meta-oe/dynamic-layers/networking-layer/recipes-core/"
 BBMASK += "meta-openstack/recipes-extended/libvirt/"
 BBMASK += "meta-webserver/recipes-(?!httpd/nginx)"
+BBMASK += "meta-python/recipes-devtools/python/python3-(?!pexpect|ptyprocess)"
+BBMASK += "meta-oe/dynamic-layers/meta-python/recipes-core/packagegroups/"
 
 # ---------------------------------------------------------------------------
 # Entire layers with 0 recipes in the container image dependency graph.
@@ -101,7 +103,7 @@ BBMASK += "meta-webserver/recipes-(?!httpd/nginx)"
 # does not warn about zero files matching BBFILE_PATTERN.
 # ---------------------------------------------------------------------------
 BBMASK += "meta-filesystems/"
-BBMASK += "meta-python/"
+
 # Warning suppression for these fully-masked layers is in meta-virt-host.conf
 # (BBFILE_PATTERN_IGNORE_EMPTY) because BitBake checks the base datastore,
 # not per-multiconfig datastores.
-- 
2.47.3

[meta-virtualization][RFC][PATCH 2/5] container-yocto-builder: drop redundant IMAGE_INSTALL

[tim.orling]

From: Tim Orling <tim.orling@konsulko.com>

We no longer need explicit IMAGE_INSTALL in multi-layer
recipes, it is handled by image-oci class.

Signed-off-by: Tim Orling <tim.orling@konsulko.com>
---
 recipes-extended/images/container-yocto-builder.bb | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/recipes-extended/images/container-yocto-builder.bb b/recipes-extended/images/container-yocto-builder.bb
index 0dba4c31..1a0a1c56 100644
--- a/recipes-extended/images/container-yocto-builder.bb
+++ b/recipes-extended/images/container-yocto-builder.bb
@@ -25,9 +25,6 @@ OCI_IMAGE_ENTRYPOINT = "/usr/bin/builder-entry.sh"
 OCI_IMAGE_AUTHOR ?= "meta-virtualization"
 OCI_IMAGE_TAG ?= "latest"
 
-# All packages listed here to trigger builds (multi-layer requirement)
-IMAGE_INSTALL = "packagegroup-yocto-builder"
-
 # No kernel needed for container
 IMAGE_CONTAINER_NO_DUMMY = "1"
 
-- 
2.47.3

[meta-virtualization][RFC][PATCH 3/5] packagegroup-yocto-builder: add additional dependencies

[tim.orling]

From: Tim Orling <tim.orling@konsulko.com>

During run-time testing of container-yocto-builder, it was
discovered that sanity testing of g++ failed and
glibc-dev, libgcc-dev, libatomic-dev are needed.
It was also discovered that we need ca-certificates for
git cloning with https:// protocol.

During a build, it was discovered that rpmdeps.real needs
libgomp. This would likely be needed for other gcc-runtime
needs, so add it to packagegroup-yocto-builder-toolchain.

In run-time testing of the bitbake-setup workflow, including
with the core/yocto/sstate-mirror-cdn fragment enabled, it
was discovered that:
* bitbake (python itself probably) needs locale-base-en-us
* bitbake-config-build needs util-linux-flock and
  util-linux-getopt
* wss:// protocol for hashequiv server needs python3-websockets
  (for sstate-mirror-cdn fragment)

For more details, see docs/container-yocto-builder.

Signed-off-by: Tim Orling <tim.orling@konsulko.com>
---
 recipes-core/packagegroups/packagegroup-yocto-builder.bb | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/recipes-core/packagegroups/packagegroup-yocto-builder.bb b/recipes-core/packagegroups/packagegroup-yocto-builder.bb
index 35080cd5..e75e50a4 100644
--- a/recipes-core/packagegroups/packagegroup-yocto-builder.bb
+++ b/recipes-core/packagegroups/packagegroup-yocto-builder.bb
@@ -68,6 +68,7 @@ RDEPENDS:packagegroup-yocto-builder-toolchain = "\
     diffutils \
     git \
     git-perltools \
+    ca-certificates \
     python3 \
     python3-modules \
     perl \
@@ -87,6 +88,10 @@ RDEPENDS:packagegroup-yocto-builder-toolchain = "\
     zstd \
     rpcsvc-proto \
     ${@bb.utils.contains('TCLIBC', 'glibc', 'glibc-utils', '', d)} \
+    ${@bb.utils.contains('TCLIBC', 'glibc', 'glibc-dev', '', d)} \
+    libgcc-dev \
+    libatomic-dev \
+    libgomp \
 "
 
 # Layer 3: Yocto-specific tools + utilities
@@ -124,4 +129,8 @@ RDEPENDS:packagegroup-yocto-builder-extras = "\
     ncurses \
     ncurses-terminfo-base \
     subversion \
+    locale-base-en-us \
+    python3-websockets \
+    util-linux-flock \
+    util-linux-getopt \
 "
-- 
2.47.3

[meta-virtualization][RFC][PATCH 4/5] container-image-multiarch: add container-yocto-builder

[tim.orling]

From: Tim Orling <tim.orling@konsulko.com>

Enable multiarch builds for x86-64 and aarch64.

Signed-off-by: Tim Orling <tim.orling@konsulko.com>
---
 recipes-containers/images/container-image-multiarch.bb | 1 +
 1 file changed, 1 insertion(+)

diff --git a/recipes-containers/images/container-image-multiarch.bb b/recipes-containers/images/container-image-multiarch.bb
index 13c4ae24..16d79410 100644
--- a/recipes-containers/images/container-image-multiarch.bb
+++ b/recipes-containers/images/container-image-multiarch.bb
@@ -16,6 +16,7 @@ CONTAINER_IMAGES ?= "\
     app-container-nginx \
     app-container-python \
     app-container-valkey \
+    container-yocto-builder \
 "
 
 inherit oci-multiarch
-- 
2.47.3

[meta-virtualization][RFC][PATCH 5/5] docs: add container-yocto-builder.md

[tim.orling]

From: Tim Orling <tim.orling@konsulko.com>

Document the steps needed to:
* enable multiarch builds of the container-yocto-builder recipe
* fix run-time errors and problems
* push the multiarch container to a registry
* run the container
* build core-image-minimal with the bitbake-setup workflow

Signed-off-by: Tim Orling <tim.orling@konsulko.com>
---
 docs/container-yocto-builder.md | 233 ++++++++++++++++++++++++++++++++
 1 file changed, 233 insertions(+)
 create mode 100644 docs/container-yocto-builder.md

diff --git a/docs/container-yocto-builder.md b/docs/container-yocto-builder.md
new file mode 100644
index 00000000..0dd28f48
--- /dev/null
+++ b/docs/container-yocto-builder.md
@@ -0,0 +1,233 @@
+# Yocto Builder Container
+
+## Build
+
+To build a multiarch `container-yocto-builder`, we need to add it to
+`CONTAINER_IMAGES` in `container-image-multiarch.bb`. This also required
+modifying `vcontainer-bbmask.inc` to allow `python3-pexpect` and its
+`python3-ptyprocess` dependency. This then exposes
+`meta-oe/dynamic-layers/meta-python` so we needed to add that to the mask.
+
+To build the container:
+
+```bash
+bitbake container-image-multiarch-container-yocto-builder
+```
+
+### Missing Dependencies
+
+During run-time testing, a few things were missing when following a `bitbake-setup` workflow.
+
+* `ca-certificates` is needed for git cloning from `https://`
+
+* `bitbake` needed `locale-base-en-us`
+
+* `wss://` for `hashserv` (with `core/yocto/sstate-mirror-cdn` fragment) needed `python3-websockets`
+
+* `bitbake-config-build` needed `util-linux-flock` and `util-linux-getopt`
+
+   ```bash
+   ERROR: The following required tools (as specified by HOSTTOOLS) appear to be unavailable in PATH, please install them in order to proceed:
+     flock getopt
+   ```
+
+* `os-release` is needed to prevent the following warning, but for our multiarch containers, distro is `vcontainer` so `vcontainer-1.0` is not in sanity tested distros:
+
+   ```bash
+   WARNING: Host distribution "unknown" has not been validated with this version of the build system; you may possibly experience unexpected failures. It is recommended that you use a tested distribution.
+   ```
+
+* We need `glibc-dev`, so following the existing pattern in `packagegroup-yocto-builder`:
+
+   ```bash
+   ${@bb.utils.contains('TCLIBC', 'glibc', 'glibc-dev', '', d)}
+   ```
+
+   ```bash
+   ERROR:  OE-core's config sanity checker detected a potential misconfiguration.
+       Either fix the cause of this error or at your own risk disable the checker (see sanity.conf).
+       Following is the list of potential problems / advisories:
+
+       An unexpected issue occurred during the C++ toolchain check: Command '['g++', '-x', 'c++', '-', '-o', '/dev/null', '-lstdc++']' returned non-zero exit status 1.An error occurred during checking the C++ toolchain for '--std=gnu++20' support. Please use a g++ compiler that supports C++20 (e.g. g++ version 10 onwards).
+   ```
+
+   ```bash
+   $ g++ --version
+   g++ (GCC) 16.1.0
+   Copyright (C) 2026 Free Software Foundation, Inc.
+   This is free software; see the source for copying conditions.  There is NO
+   warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+   builder@c9a0678daa85:/workdir/bitbake-builds/poky-master/build$ g++ -x c++ -lstd++
+   /usr/bin/x86_64-poky-linux-ld: cannot find Scrt1.o: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find crti.o: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find crtbeginS.o: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -lstd++: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -lm: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -lgcc_s: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -lgcc: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -latomic_asneeded: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -lc: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -lgcc_s: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -lgcc: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find crtendS.o: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find crtn.o: No such file or directory
+   collect2: error: ld returned 1 exit status
+   ```
+
+* We need `libgcc-dev`:
+
+   ```bash
+   $ g++ -x c++ -lstdc++
+   /usr/bin/x86_64-poky-linux-ld: cannot find crtbeginS.o: No such file or directory
+   collect2: error: ld returned 1 exit status
+   ```
+
+   ```bash
+   $ oe-pkgdata-util -p tmp-container-aarch64/pkgdata/qemuarm64/ list-pkg-files libgcc-dev
+   libgcc-dev:
+     /usr/lib/aarch64-poky-linux/16.1.0/crtbegin.o
+     /usr/lib/aarch64-poky-linux/16.1.0/crtbeginS.o
+     /usr/lib/aarch64-poky-linux/16.1.0/crtbeginT.o
+     /usr/lib/aarch64-poky-linux/16.1.0/crtend.o
+     /usr/lib/aarch64-poky-linux/16.1.0/crtendS.o
+     /usr/lib/aarch64-poky-linux/16.1.0/crtfastmath.o
+     /usr/lib/aarch64-poky-linux/16.1.0/libgcc.a
+     /usr/lib/aarch64-poky-linux/16.1.0/libgcc_eh.a
+     /usr/lib/aarch64-poky-linux/16.1.0/libgcov.a
+     /usr/lib/libgcc_s.so
+     /usr/lib/libgcc_s_asneeded.so
+   ```
+
+* We need `libatomic-dev`:
+
+   ```bash
+   $ g++ -x c++ -lstdc++
+   /usr/bin/x86_64-poky-linux-ld: cannot find -latomic_asneeded: No such file or directory
+   collect2: error: ld returned 1 exit status
+   ```
+
+   ```bash
+   $ oe-pkgdata-util -p tmp-container-aarch64/pkgdata/qemuarm64/ list-pkg-files libatomic-dev
+   libatomic-dev:
+     /usr/lib/libatomic.so
+     /usr/lib/libatomic_asneeded.so
+   ```
+
+* We need `libgomp`:
+
+   ```bash
+   ERROR: base-files-3.0.14-r0 do_package: Fatal errors occurred in subprocesses:
+   Command '['/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/recipe-sysroot-native/usr/lib/rpm/rpmdeps', '--alldeps', '--define', '__font_provides %{nil}', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/hosts', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/mtab', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/nsswitch.conf', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/issue', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/motd', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/fstab', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/host.conf', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/issue.net', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/hostname', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/shells', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/profile', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/skel/.bashrc', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/skel/.profile', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/var/lock']' returned non-zero exit status 127.
+   Subprocess output:/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/recipe-sysroot-native/usr/lib/rpm/rpmdeps: error while loading shared libraries: libgomp.so.1: cannot open shared object file: No such file or directory
+
+   ERROR: Logfile of failure stored in: /workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/temp/log.do_package.136007
+   ERROR: Task (/workdir/bitbake-builds/poky-master/layers/openembedded-core/meta/recipes-core/base-files/base-files_3.0.14.bb:do_package) failed with exit code '1'
+   NOTE: Tasks Summary: Attempted 4002 tasks of which 2754 didn't need to be rerun and 1 failed.
+
+   Summary: 1 task failed:
+     /workdir/bitbake-builds/poky-master/layers/openembedded-core/meta/recipes-core/base-files/base-files_3.0.14.bb:do_package
+       log: /workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/temp/log.do_package.136007
+   Summary: There was 1 WARNING message.
+   Summary: There was 1 ERROR message, returning a non-zero exit code.
+   ```
+
+   The same was seen when building `gcc-runtime`.
+
+   According to Claude, this is yet another missing dependency in the container:
+
+   ```text
+   ● Root cause found. Your yocto-builder container's own rootfs is missing libgomp.so.1 system-wide — it's not a bitbake config/sstate
+   problem, it's a gap in the container image itself.
+   ```
+
+## Push
+
+To push to a container registry:
+
+```bash
+ bitbake skopeo-native -c addto_recipe_sysroot
+ oe-run-native skopeo-native skopeo copy --all \
+   --dest-authfile /home/user/.config/containers/auth.json \
+   oci:tmp/deploy/images/qemux86-64/container-image-multiarch-container-yocto-builder-multiarch-oci/ \
+   docker://my.registry.io/user/yocto-builder:latest
+```
+
+## Run
+
+This container is different compared to the CROPS `poky-container`, so we need
+a few more arguments on the command line.
+
+```bash
+docker pull my.registry.io/user/yocto-builder:latest
+docker run --privileged -d \
+  --name yocto_builder \
+  --rm -e BUILDER_UID=$(id -u) -e BUILDER_GID=$(id -g) \
+  -v /path/to/workspace-yocto-builder:/workdir \
+  my.registry.io/user/yocto-builder:latest
+```
+
+To get to a shell:
+
+```bash
+docker exec -it -w /workdir -u builder yocto_builder bash
+```
+
+You may want a different prompt, more like `poky-container`:
+
+```bash
+PS1="\u@\h:\w\$ "
+```
+
+At this point, you should be able to follow the [Quick Build][quick-build] guide in the [Yocto Project Documentation][yocto-docs].
+
+## Building `core-image-minimal`
+
+1. Clone `bitbake` so we can run `bitbake-setup`:
+
+   ```bash
+   git clone https://git.openembedded.org/bitbake.git
+   ```
+
+2. Setup `poky-master` non-interactively:
+
+   ```bash
+   bitbake/bin/bitbake-setup init --non-interactive poky-master poky distro/poky machine/qemux86-64
+   ```
+
+3. Initialize the `poky-master` build environment:
+
+   ```bash
+   . bitbake-builds/poky-master/build/init-build-env
+   ```
+
+4. (Optional) Enable config fragments:
+
+   ```bash
+   bitbake-config-build enable-fragment core/yocto/root-login-with-empty-password
+   bitbake-config-build enable-fragment core/yocto/sbom-cve-check
+   bitbake-config-build enable-fragment core/yocto/sstate-mirror-cdn
+   ```
+
+   You can also pass multiple fragments:
+
+   ```bash
+   bitbake-config-build enable-fragment core/yocto/root-login-with-empty-password  core/yocto/sbom-cve-check core/yocto/sstate-mirror-cdn
+   ```
+
+5. Build `core-image-minimal`
+
+   ```bash
+   bitbake core-image-minimal
+   ```
+
+6. Run `core-image-minimal`
+
+   ```bash
+   runqemu nographic slirp snapshot
+   ```
+
+<!-- References -->
+
+[quick-build]: <https://docs.yoctoproject.org/brief-yoctoprojectqs/index.html>  
+[yocto-docs]: <https://docs.yoctoproject.org>
-- 
2.47.3

Re: [meta-virtualization][RFC][PATCH 2/5] container-yocto-builder: drop redundant IMAGE_INSTALL

[Bruce Ashfield]

ack'd, staging on master-next.

Bruce

Re: [meta-virtualization][RFC][PATCH 3/5] packagegroup-yocto-builder: add additional dependencies

[Bruce Ashfield]

ack'd, staging on master-next.

Bruce

Re: [meta-virtualization][RFC][PATCH 4/5] container-image-multiarch: add container-yocto-builder

[Bruce Ashfield]

ack'd, staging on master-next.

Bruce

Re: [meta-virtualization][RFC][PATCH 5/5] docs: add container-yocto-builder.md

[Bruce Ashfield]

ack'd, staging on master-next.

Bruce

Re: [meta-virtualization][RFC][PATCH 1/5] vcontainer-bbmask.inc: add python3-pexpect,-ptyprocess

[Bruce Ashfield]

Thanks Tim. I'm taking 2/5 through 5/5 directly (verified 2/5 against
image-oci.bbclass — the auto-fold of OCI_LAYERS `packages:` entries
into IMAGE_INSTALL at line ~389 is exactly the duplication this drops,
so it's a clean removal). 3/5's added deps all trace to concrete
failures documented in 5/5, which is a great artifact.

One question before I take this one:

The commit says python3-pexpect is needed "during run-time testing
with the bitbake-setup workflow." What in the built container actually
imports/exec's pexpect at runtime? If it's the vcontainer test suite
driving the container from outside, pexpect belongs on the test host,
not baked into the image. If it's something inside the container —
bitbake-setup itself, a Yocto tool, or a test harness that runs
in-container — that's legitimate, but a one-line note in the commit
message naming the caller would help future readers understand why
we're carving a hole in the meta-python mask.

If it's just needed for our own vcontainer test runner and not by
anything the container itself invokes, I'd rather leave the meta-python
mask intact and put pexpect on the host that runs the tests.

Bruce

Re: [meta-virtualization][RFC][PATCH 1/5] vcontainer-bbmask.inc: add python3-pexpect,-ptyprocess

[Tim Orling]

On Tue, Jul 28, 2026 at 10:47:14AM -0700, Bruce Ashfield wrote:
> Thanks Tim. I'm taking 2/5 through 5/5 directly (verified 2/5 against
> image-oci.bbclass — the auto-fold of OCI_LAYERS `packages:` entries
> into IMAGE_INSTALL at line ~389 is exactly the duplication this drops,
> so it's a clean removal). 3/5's added deps all trace to concrete
> failures documented in 5/5, which is a great artifact.
> 
> One question before I take this one:
> 
> The commit says python3-pexpect is needed "during run-time testing
> with the bitbake-setup workflow." What in the built container actually

This was a mistake on my part, not capturing the original reason.

It was a build-time error satisfying the RDEPENDS for
packagegroup-yocto-build-extras which I am fairly certain you added
because you were trying to satisfy "Build Host Packages" [1] or
similar.

Ignoring the yocto-docs history, looking purely at openembedded-core
the only place I found an obvious import is in the SerialConnection
class in [2]. However, for a fully functional container-yocto-builder
built with mc:container-* multiconfig, we would still need this.

I have updated the commit message and added a comment in v2.

I have also updated docs/container-yocto-builder.md to better reflect
this reason and will also send a v2 for that patch.

> imports/exec's pexpect at runtime? If it's the vcontainer test suite
> driving the container from outside, pexpect belongs on the test host,
> not baked into the image. If it's something inside the container —
> bitbake-setup itself, a Yocto tool, or a test harness that runs
> in-container — that's legitimate, but a one-line note in the commit
> message naming the caller would help future readers understand why
> we're carving a hole in the meta-python mask.
> 
> If it's just needed for our own vcontainer test runner and not by
> anything the container itself invokes, I'd rather leave the meta-python
> mask intact and put pexpect on the host that runs the tests.
> 
> Bruce
> 

[1] https://docs.yoctoproject.org/brief-yoctoprojectqs/index.html#build-host-packages
[2] https://git.openembedded.org/openembedded-core/tree/meta/lib/oeqa/core/target/serial.py#n258

[PATCH v2 1/5] vcontainer-bbmask.inc: add python3-pexpect,-ptyprocess

[tim.orling]

From: Tim Orling <tim.orling@konsulko.com>

For container-yocto-builder, the container is the "host" and so
we need the "Build Host Packages" equivalent in [1]. When
we are building with mc:container-aarch64,-x86-64 multiconfig
and the vcontainer distro, we need python3-pexpect and its
dependency python3-ptyprocess to fulfill
packagegroup-yocto-builder-extras. Otherwise we see a build-time
error like:

ERROR: Nothing RPROVIDES 'python3-pexpect' (but mc:container-aarch64:
.../meta-virtualization/recipes-core/packagegroups/packagegroup-yocto-builder.bb
RDEPENDS on or otherwise requires it)
NOTE: Runtime target 'python3-pexpect' is unbuildable, removing...
Missing or unbuildable dependency chain was: ['python3-pexpect']
ERROR: Required build target 'packagegroup-yocto-builder' has no buildable providers.
Missing or unbuildable dependency chain was: ['packagegroup-yocto-builder', 'python3-pexpect']

Remove the layer-wide meta-python BBMASK and allow these
specific recipes.

Once meta-python is allowed, there was an error for
meta-oe/dynamic-layers/meta-python which we do not need for the
above recipes. It can be enabled in the future when needed.

[1] https://docs.yoctoproject.org/brief-yoctoprojectqs/index.html#build-host-packages
Signed-off-by: Tim Orling <tim.orling@konsulko.com>
---
 conf/distro/include/vcontainer-bbmask.inc | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/conf/distro/include/vcontainer-bbmask.inc b/conf/distro/include/vcontainer-bbmask.inc
index 0c9b8b02..572ebc4a 100644
--- a/conf/distro/include/vcontainer-bbmask.inc
+++ b/conf/distro/include/vcontainer-bbmask.inc
@@ -94,6 +94,9 @@ BBMASK += "meta-openstack/recipes-dbs/postgresql/"
 BBMASK += "meta-oe/dynamic-layers/networking-layer/recipes-core/"
 BBMASK += "meta-openstack/recipes-extended/libvirt/"
 BBMASK += "meta-webserver/recipes-(?!httpd/nginx)"
+# To satisfy RDEPENDS for packagegroup-yocto-builder-extras in mc:container-*
+BBMASK += "meta-python/recipes-devtools/python/python3-(?!pexpect|ptyprocess)"
+BBMASK += "meta-oe/dynamic-layers/meta-python/recipes-core/packagegroups/"
 
 # ---------------------------------------------------------------------------
 # Entire layers with 0 recipes in the container image dependency graph.
@@ -101,7 +104,7 @@ BBMASK += "meta-webserver/recipes-(?!httpd/nginx)"
 # does not warn about zero files matching BBFILE_PATTERN.
 # ---------------------------------------------------------------------------
 BBMASK += "meta-filesystems/"
-BBMASK += "meta-python/"
+
 # Warning suppression for these fully-masked layers is in meta-virt-host.conf
 # (BBFILE_PATTERN_IGNORE_EMPTY) because BitBake checks the base datastore,
 # not per-multiconfig datastores.
-- 
2.43.0

[PATCH v2 5/5] docs: add container-yocto-builder.md

[tim.orling]

From: Tim Orling <tim.orling@konsulko.com>

Document the steps needed to:
* enable multiarch builds of the container-yocto-builder recipe
* fix run-time errors and problems
* push the multiarch container to a registry
* run the container
* build core-image-minimal with the bitbake-setup workflow

Signed-off-by: Tim Orling <tim.orling@konsulko.com>
---
 docs/container-yocto-builder.md | 234 ++++++++++++++++++++++++++++++++
 1 file changed, 234 insertions(+)
 create mode 100644 docs/container-yocto-builder.md

diff --git a/docs/container-yocto-builder.md b/docs/container-yocto-builder.md
new file mode 100644
index 00000000..ea82f3f8
--- /dev/null
+++ b/docs/container-yocto-builder.md
@@ -0,0 +1,234 @@
+# Yocto Builder Container
+
+## Build
+
+To build a multiarch `container-yocto-builder`, we need to add it to
+`CONTAINER_IMAGES` in `container-image-multiarch.bb`. This also required
+modifying `vcontainer-bbmask.inc` to allow `python3-pexpect` and its
+`python3-ptyprocess` dependency in order to satisfy the dependencies in
+`packagegroup-yocto-builder-extras`. This then exposes
+`meta-oe/dynamic-layers/meta-python` so we needed to add that to the mask.
+
+To build the container:
+
+```bash
+bitbake container-image-multiarch-container-yocto-builder
+```
+
+### Missing Dependencies
+
+During run-time testing, a few things were missing when following a `bitbake-setup` workflow.
+
+* `ca-certificates` is needed for git cloning from `https://`
+
+* `bitbake` needed `locale-base-en-us`
+
+* `wss://` for `hashserv` (with `core/yocto/sstate-mirror-cdn` fragment) needed `python3-websockets`
+
+* `bitbake-config-build` needed `util-linux-flock` and `util-linux-getopt`
+
+   ```bash
+   ERROR: The following required tools (as specified by HOSTTOOLS) appear to be unavailable in PATH, please install them in order to proceed:
+     flock getopt
+   ```
+
+* `os-release` is needed to prevent the following warning, but for our multiarch containers, distro is `vcontainer` so `vcontainer-1.0` is not in sanity tested distros:
+
+   ```bash
+   WARNING: Host distribution "unknown" has not been validated with this version of the build system; you may possibly experience unexpected failures. It is recommended that you use a tested distribution.
+   ```
+
+* We need `glibc-dev`, so following the existing pattern in `packagegroup-yocto-builder`:
+
+   ```bash
+   ${@bb.utils.contains('TCLIBC', 'glibc', 'glibc-dev', '', d)}
+   ```
+
+   ```bash
+   ERROR:  OE-core's config sanity checker detected a potential misconfiguration.
+       Either fix the cause of this error or at your own risk disable the checker (see sanity.conf).
+       Following is the list of potential problems / advisories:
+
+       An unexpected issue occurred during the C++ toolchain check: Command '['g++', '-x', 'c++', '-', '-o', '/dev/null', '-lstdc++']' returned non-zero exit status 1.An error occurred during checking the C++ toolchain for '--std=gnu++20' support. Please use a g++ compiler that supports C++20 (e.g. g++ version 10 onwards).
+   ```
+
+   ```bash
+   $ g++ --version
+   g++ (GCC) 16.1.0
+   Copyright (C) 2026 Free Software Foundation, Inc.
+   This is free software; see the source for copying conditions.  There is NO
+   warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+   builder@c9a0678daa85:/workdir/bitbake-builds/poky-master/build$ g++ -x c++ -lstd++
+   /usr/bin/x86_64-poky-linux-ld: cannot find Scrt1.o: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find crti.o: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find crtbeginS.o: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -lstd++: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -lm: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -lgcc_s: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -lgcc: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -latomic_asneeded: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -lc: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -lgcc_s: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find -lgcc: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find crtendS.o: No such file or directory
+   /usr/bin/x86_64-poky-linux-ld: cannot find crtn.o: No such file or directory
+   collect2: error: ld returned 1 exit status
+   ```
+
+* We need `libgcc-dev`:
+
+   ```bash
+   $ g++ -x c++ -lstdc++
+   /usr/bin/x86_64-poky-linux-ld: cannot find crtbeginS.o: No such file or directory
+   collect2: error: ld returned 1 exit status
+   ```
+
+   ```bash
+   $ oe-pkgdata-util -p tmp-container-aarch64/pkgdata/qemuarm64/ list-pkg-files libgcc-dev
+   libgcc-dev:
+     /usr/lib/aarch64-poky-linux/16.1.0/crtbegin.o
+     /usr/lib/aarch64-poky-linux/16.1.0/crtbeginS.o
+     /usr/lib/aarch64-poky-linux/16.1.0/crtbeginT.o
+     /usr/lib/aarch64-poky-linux/16.1.0/crtend.o
+     /usr/lib/aarch64-poky-linux/16.1.0/crtendS.o
+     /usr/lib/aarch64-poky-linux/16.1.0/crtfastmath.o
+     /usr/lib/aarch64-poky-linux/16.1.0/libgcc.a
+     /usr/lib/aarch64-poky-linux/16.1.0/libgcc_eh.a
+     /usr/lib/aarch64-poky-linux/16.1.0/libgcov.a
+     /usr/lib/libgcc_s.so
+     /usr/lib/libgcc_s_asneeded.so
+   ```
+
+* We need `libatomic-dev`:
+
+   ```bash
+   $ g++ -x c++ -lstdc++
+   /usr/bin/x86_64-poky-linux-ld: cannot find -latomic_asneeded: No such file or directory
+   collect2: error: ld returned 1 exit status
+   ```
+
+   ```bash
+   $ oe-pkgdata-util -p tmp-container-aarch64/pkgdata/qemuarm64/ list-pkg-files libatomic-dev
+   libatomic-dev:
+     /usr/lib/libatomic.so
+     /usr/lib/libatomic_asneeded.so
+   ```
+
+* We need `libgomp`:
+
+   ```bash
+   ERROR: base-files-3.0.14-r0 do_package: Fatal errors occurred in subprocesses:
+   Command '['/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/recipe-sysroot-native/usr/lib/rpm/rpmdeps', '--alldeps', '--define', '__font_provides %{nil}', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/hosts', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/mtab', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/nsswitch.conf', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/issue', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/motd', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/fstab', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/host.conf', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/issue.net', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/hostname', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/shells', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/profile', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/skel/.bashrc', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/etc/skel/.profile', '/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/packages-split/base-files/var/lock']' returned non-zero exit status 127.
+   Subprocess output:/workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/recipe-sysroot-native/usr/lib/rpm/rpmdeps: error while loading shared libraries: libgomp.so.1: cannot open shared object file: No such file or directory
+
+   ERROR: Logfile of failure stored in: /workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/temp/log.do_package.136007
+   ERROR: Task (/workdir/bitbake-builds/poky-master/layers/openembedded-core/meta/recipes-core/base-files/base-files_3.0.14.bb:do_package) failed with exit code '1'
+   NOTE: Tasks Summary: Attempted 4002 tasks of which 2754 didn't need to be rerun and 1 failed.
+
+   Summary: 1 task failed:
+     /workdir/bitbake-builds/poky-master/layers/openembedded-core/meta/recipes-core/base-files/base-files_3.0.14.bb:do_package
+       log: /workdir/bitbake-builds/poky-master/build/tmp/work/qemux86_64-poky-linux/base-files/3.0.14/temp/log.do_package.136007
+   Summary: There was 1 WARNING message.
+   Summary: There was 1 ERROR message, returning a non-zero exit code.
+   ```
+
+   The same was seen when building `gcc-runtime`.
+
+   According to Claude, this is yet another missing dependency in the container:
+
+   ```text
+   ● Root cause found. Your yocto-builder container's own rootfs is missing libgomp.so.1 system-wide — it's not a bitbake config/sstate
+   problem, it's a gap in the container image itself.
+   ```
+
+## Push
+
+To push to a container registry:
+
+```bash
+ bitbake skopeo-native -c addto_recipe_sysroot
+ oe-run-native skopeo-native skopeo copy --all \
+   --dest-authfile /home/user/.config/containers/auth.json \
+   oci:tmp/deploy/images/qemux86-64/container-image-multiarch-container-yocto-builder-multiarch-oci/ \
+   docker://my.registry.io/user/yocto-builder:latest
+```
+
+## Run
+
+This container is different compared to the CROPS `poky-container`, so we need
+a few more arguments on the command line.
+
+```bash
+docker pull my.registry.io/user/yocto-builder:latest
+docker run --privileged -d \
+  --name yocto_builder \
+  --rm -e BUILDER_UID=$(id -u) -e BUILDER_GID=$(id -g) \
+  -v /path/to/workspace-yocto-builder:/workdir \
+  my.registry.io/user/yocto-builder:latest
+```
+
+To get to a shell:
+
+```bash
+docker exec -it -w /workdir -u builder yocto_builder bash
+```
+
+You may want a different prompt, more like `poky-container`:
+
+```bash
+PS1="\u@\h:\w\$ "
+```
+
+At this point, you should be able to follow the [Quick Build][quick-build] guide in the [Yocto Project Documentation][yocto-docs].
+
+## Building `core-image-minimal`
+
+1. Clone `bitbake` so we can run `bitbake-setup`:
+
+   ```bash
+   git clone https://git.openembedded.org/bitbake.git
+   ```
+
+2. Setup `poky-master` non-interactively:
+
+   ```bash
+   bitbake/bin/bitbake-setup init --non-interactive poky-master poky distro/poky machine/qemux86-64
+   ```
+
+3. Initialize the `poky-master` build environment:
+
+   ```bash
+   . bitbake-builds/poky-master/build/init-build-env
+   ```
+
+4. (Optional) Enable config fragments:
+
+   ```bash
+   bitbake-config-build enable-fragment core/yocto/root-login-with-empty-password
+   bitbake-config-build enable-fragment core/yocto/sbom-cve-check
+   bitbake-config-build enable-fragment core/yocto/sstate-mirror-cdn
+   ```
+
+   You can also pass multiple fragments:
+
+   ```bash
+   bitbake-config-build enable-fragment core/yocto/root-login-with-empty-password  core/yocto/sbom-cve-check core/yocto/sstate-mirror-cdn
+   ```
+
+5. Build `core-image-minimal`
+
+   ```bash
+   bitbake core-image-minimal
+   ```
+
+6. Run `core-image-minimal`
+
+   ```bash
+   runqemu nographic slirp snapshot
+   ```
+
+<!-- References -->
+
+[quick-build]: <https://docs.yoctoproject.org/brief-yoctoprojectqs/index.html>  
+[yocto-docs]: <https://docs.yoctoproject.org>
-- 
2.43.0