Fetchcontent doesn't fetch from git if you specify the full SHA hash
If you do e.g.:
FetchContent_Declare(apps GIT_REPOSITORY url/for/apps.git GIT_TAG bcc8e615c1f3b5ea250b49ebcadb5549dd71c5de ) FetchContent_GetProperties(apps) if (NOT apps_POPULATED) FetchContent_Populate(apps) endif()
then when you update the hash, cmake will not fetch from the repository again. Instead you get
fatal: reference is not a tree: bcc8e615c1f3b5ea250b49ebcadb5549dd71c5de. This seems to be because
git rev-parse, which returns the hash without error when you give it any full hash. If you delete some trailing characters from the hash it works fine.