git was missing

Dockerfile

@@ -9,3 +9,4 @@ RUN pip install sphinx_rtd_theme
 RUN apk add texlive-full
 RUN apk add make
 RUN apk add rsync
+RUN apk add git

VERSION

@@ -2,4 +2,4 @@ VERSION_MAJOR = 0
 VERSION_MINOR = 0
 PATCHLEVEL = 9
 VERSION_TWEAK = 4
-EXTRAVERSION = rc2
+EXTRAVERSION = rc3

gitlab-build.sh

@@ -41,6 +41,7 @@ rm -rf public/$CI_COMMIT_BRANCH/latex
 
 elif [ "$CI_COMMIT_TAG" != "" ]; then
 
+sudo apk add git
 # Find which branch has the tag commit
 export GIT_BRANCH=$(git branch -a --contains tags/$CI_COMMIT_TAG | grep origin | sed 's/.*origin\///')
 echo "**** Releasing $GIT_BRANCH version $CI_COMMIT_TAG on docs.beagleboard.org (source from $CI_PROJECT_NAMESPACE) ****"