[Buildroot] Building cargo with per-package directories

[Eric Le Bihan <eric.le.bihan.dev@free.fr>]

Hi!
On 2018-12-11 17:12, Thomas Petazzoni wrote:
> Hello ?ric,
>
> As you probably know, I'm working on support for per-package
> directories, which will allow to do top-level parallel in a reliable
> way. As part of this effort, I've started an autobuilder that uses
> per-package directories, and one of the package that is failing a lot
> is host-cargo.
>
> It fails like this:
>
>   = note: /usr/bin/ld: cannot find -lhttp_parser
>           collect2: error: ld returned 1 exit status
>
> error: aborting due to previous error
> error: Could not compile `cargo`.
>
> The problem is that while libhttp_parser gets built properly, cargo is
> not passing the appropriate -L flag to cargo's per-package host/lib
> directory. So the linker doesn't find the libhttp_parser library, and
> bails out.
>
> I've tried to look into this, but really the cargo build system is very
> unique and weird, and I'm having a hard time finding my way. Do you
> think you could help me a bit on this topic ?

Of course!

>
> To reproduce, you need a machine where libhttp_parser is not installed
> system-wide (so either remove it from your system, or build in a
> chroot/docker/VM). Then, take this branch:
>
>   https://git.bootlin.com/users/thomas-petazzoni/buildroot/log/?h=ppsh-v7-work
>
> And build the following defconfig:
>
> BR2_arm=y
> BR2_cortex_a9=y
> BR2_ARM_ENABLE_VFP=y
> BR2_PER_PACKAGE_DIRECTORIES=y
> BR2_TOOLCHAIN_EXTERNAL=y
> BR2_TOOLCHAIN_EXTERNAL_CUSTOM=y
> BR2_TOOLCHAIN_EXTERNAL_DOWNLOAD=y
> BR2_TOOLCHAIN_EXTERNAL_URL="http://autobuild.buildroot.org/toolchains/tarballs/br-arm-cortex-a9-glibc-2018.05.tar.bz2"
> BR2_TOOLCHAIN_EXTERNAL_GCC_7=y
> BR2_TOOLCHAIN_EXTERNAL_HEADERS_4_16=y
> BR2_TOOLCHAIN_EXTERNAL_CUSTOM_GLIBC=y
> BR2_TOOLCHAIN_EXTERNAL_CXX=y
> BR2_INIT_NONE=y
> BR2_SYSTEM_BIN_SH_NONE=y
> # BR2_PACKAGE_BUSYBOX is not set
> # BR2_TARGET_ROOTFS_TAR is not set
> BR2_PACKAGE_HOST_CARGO=y
>
> You should get this failure:
>
>   http://code.bulix.org/fxjgrv-520980?raw
>
> Thanks in advance for your support,

I added your clone as remote, checked out ppsh-v7-work branch and
launched a Debian Stretch chroot. I'll keep you posted on the result.

Regards,

--
ELB