Github CI can't fetch submodule from git:// GNU savannah, unless it refers to upstream HEAD

[HinTak]

I have a submodule refers to
git://git.sv.nongnu.org/freetype/freetype2.git` . This is the canonical place for freetype for about 2 decades, until recent move to gitlab.freedesktop . It seems that it works only if the submodule refers to the head of upstream. When upstream freetype2 moves forward, github CI cannot fetch the older commit.

I think github CI doesn't actually do 'git submodule update --init' (with --depth 1) directly, and do something else, so it only works when the submodule points to upstream head at the time. It cannot fetch older commits.

It is not a deal breaker - freetype doesn’t move that fast, and it is a good reminder for me to update the submodule to point to current head, but still...

[HinTak]

The repo in question is https://github.com/HinTak/freetype2-demos-skia - for people who want to experiment, try rolling backwards slightly freetype2 or freetype2-demo. git submodule update --init works, but that does not seems to be what github CI is using directly.