doc: More debug messages (#3315)

The previous commit was inconclusive

REVERT ME

.travis.yml

@@ -335,3 +335,4 @@ after_success:
       test -f build/luacov.stats.out || { echo 'build/luacov.stats.out does not exist.'; return 1; }
       luacov-coveralls --verbose --merge
     fi
+  - echo "The build finished normally"

build-utils/travis-apidoc.sh

@@ -8,7 +8,7 @@
 #
 # NOTE: stdout/stderr might/should be discarded to not leak sensitive information.
 
-echo "Post-processing (API) documentation."
+echo "Post-processing (API) documentation. DEBUG 2021"
 echo "TRAVIS_PULL_REQUEST: $TRAVIS_PULL_REQUEST"
 echo "TRAVIS_BRANCH: $TRAVIS_BRANCH"
 
@@ -110,6 +110,10 @@ git commit -m "[boilerplate] $COMMIT_MSG"
 RELEVANT_REV="$(git rev-parse --short HEAD)"
 #FIXME git tag -d _old
 
+echo BEGIN BEFORE CHECKOUT
+git log --graph | head -n 100
+echo END BEFORE CHECKOUT $RELEVANT_REV
+
 git checkout "$BRANCH"
 OLD_REV="$(git rev-parse --short HEAD)"
 if [ "$TRAVIS_PULL_REQUEST" != false ]; then