gitlab: aggressively avoid extra GIT data

This avoids fetching blobs and tree references for branches we are not
going to worry about. Also skip tag references which are similarly not
useful and keep the default --prune. This keeps the .git data to
around 100M rather than the ~400M even a shallow clone takes.

So we can check the savings we also run a quick du while setting up
the build.

We also have to have special settings of GIT_FETCH_EXTRA_FLAGS for the
Windows build (git too old?) and the migration legacy test where we
build an older QEMU alongside the main one.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

.gitlab-ci.d/base.yml

@@ -24,6 +24,10 @@ variables:
     # Each script line from will be in a collapsible section in the job output
     # and show the duration of each line.
     FF_SCRIPT_SECTIONS: 1
+    # The project has a fairly fat GIT repo so we try and avoid bringing in things
+    # we don't need. The --filter options avoid blobs and tree references we aren't going to use
+    # and we also avoid fetching tags.
+    GIT_FETCH_EXTRA_FLAGS: --filter=blob:none --filter=tree:0 --no-tags --prune --quiet
 
   interruptible: true
 

.gitlab-ci.d/buildtest-template.yml

@@ -14,6 +14,7 @@
     - export CCACHE_DIR="$CCACHE_BASEDIR/ccache"
     - export CCACHE_MAXSIZE="500M"
     - export PATH="$CCACHE_WRAPPERSDIR:$PATH"
+    - du -sh .git
     - mkdir build
     - cd build
     - ccache --zero-stats

.gitlab-ci.d/buildtest.yml

@@ -187,6 +187,8 @@ build-previous-qemu:
   variables:
     IMAGE: opensuse-leap
     TARGETS: x86_64-softmmu aarch64-softmmu
+    # Override the default flags as we need more to grab the old version
+    GIT_FETCH_EXTRA_FLAGS: --prune --quiet
   before_script:
     - export QEMU_PREV_VERSION="$(sed 's/\([0-9.]*\)\.[0-9]*/v\1.0/' VERSION)"
     - git remote add upstream https://gitlab.com/qemu-project/qemu

.gitlab-ci.d/windows.yml

@@ -28,6 +28,8 @@ msys2-64bit:
     # qTests don't run successfully with "--without-default-devices",
     # so let's exclude the qtests from CI for now.
     TEST_ARGS: --no-suite qtest
+    # The Windows git is a bit older so override the default
+    GIT_FETCH_EXTRA_FLAGS: --no-tags --prune --quiet
   artifacts:
     name: "$CI_JOB_NAME-$CI_COMMIT_REF_SLUG"
     expire_in: 7 days