[XEN PATCH] CI: Add and use ccache in build-each-commit job

[Anthony PERARD <anthony@xenproject.org>]

From: Anthony PERARD <anthony.perard@vates.tech>

Signed-off-by: Anthony PERARD <anthony.perard@vates.tech>
---

Notes:
    The job build-each-commit is a bit faster, and can do about twice as
    much builds.
    
        https://gitlab.com/xen-project/people/anthonyper/xen/-/jobs/10785719529
    
    I haven't updated the container yet.

 automation/build/debian/12-x86_64.dockerfile | 3 +++
 automation/gitlab-ci/build-each-commit.sh    | 5 +++++
 2 files changed, 8 insertions(+)

diff --git a/automation/build/debian/12-x86_64.dockerfile b/automation/build/debian/12-x86_64.dockerfile
index 6e0a403f64..e26a19079e 100644
--- a/automation/build/debian/12-x86_64.dockerfile
+++ b/automation/build/debian/12-x86_64.dockerfile
@@ -54,6 +54,9 @@ RUN <<EOF
         expect
         qemu-system-x86
 
+        # for build-each-commit-gcc
+        ccache
+
         # for qemu-alpine-x86_64-gcc
         busybox-static
         cpio
diff --git a/automation/gitlab-ci/build-each-commit.sh b/automation/gitlab-ci/build-each-commit.sh
index 08fddecbbe..166392fffd 100755
--- a/automation/gitlab-ci/build-each-commit.sh
+++ b/automation/gitlab-ci/build-each-commit.sh
@@ -12,6 +12,11 @@ if [[ $? -ne 0 ]]; then
     exit 0
 fi
 
+if [ -d /usr/lib/ccache ]; then
+    echo "Building with ccache"
+    PATH="/usr/lib/ccache:$PATH"
+fi
+
 echo "Building ${BASE}..${TIP}"
 
 NON_SYMBOLIC_REF=1 ./automation/scripts/build-test.sh ${BASE} ${TIP} \
-- 
Anthony PERARD