[tracker/wip/carlosg/fix-coverage-percentage] ci: Rebuild tree before running tests

[Carlos Garnacho <carlosg src gnome org>]

commit 023712048a7b5a928cc02a4623f3790003044411
Author: Carlos Garnacho <carlosg gnome org>
Date:   Mon Mar 21 14:24:51 2022 +0100

    ci: Rebuild tree before running tests
    
    For some reason, gcc or gcovr do not appreciate intermediate gcda/gcno
    files being transferred between CI runners. Ensure to rebuild the
    tree so that these are freshly created.
    
    Fixes the wonky coverage reports seen lately, as individual test
    runs had these fluctuations that made them report as little as 10%
    covered, quite far from the more accurate ~77% we get in the correct
    runs.

 .gitlab-ci.yml | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 8c7f91ed6..ff06146bd 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -287,6 +287,7 @@ build-alpine-latest@x86_64:
       # whole environment for every failed test, and that gives a whole
       # screenful of junk each time unless we strip these.
       unset $(env|grep -o '^CI_[^=]*')
+      ninja clean; ninja
       env LANG=C.UTF-8 LC_ALL=C.UTF-8 dbus-run-session meson test -t $MESON_TEST_TIMEOUT_MULTIPLIER 
--print-errorlogs ${MESON_TEST_EXTRA_ARGS}
   after_script:
     - pushd build