[rush] Git version requirements are a bit high?

[Faithfinder]

So, I'm working on my company's build pipeline right now, and I've noticed one unfortunate thing - official docker node images, which I think are most likely to be used with rush, all have git version 2.11 installed rather than anything later. After some digging you can also use node:x-buster images which contain git 2.20.
Since rush wants 2.30, I'd need to install it into the image manually, and with images based on Debian rather than Ubuntu it's not a straightforward process (I think I need to build from source? Maybe I'll find a simpler way, but it doesn't google easily).

While I understand that it's not entirely rush's problem, I do wonder if minimal version really needs to be that high?

[chengcyber]

Share my changes to Dockerfile, hope it helps

Install git 2.32.0 from source file at Debian8 system

# install git 2.32.0
RUN apt-get purge -y git && apt-get update \
    && apt-get install -y libcurl4-gnutls-dev libexpat1-dev gettext libz-dev libssl-dev asciidoc xmlto docbook2x \
    && wget https://github.com/git/git/archive/v2.32.0.tar.gz \
    && tar zxvf v2.32.0.tar.gz \
    && cd git-2.32.0 \
    && make configure \
    && ./configure --prefix=/usr \
    && make all \
    && sudo make install

[Faithfinder]

Thanks! That helps me indeed, but the question is sorta philosophical.

[chengcyber]

Agreed. Either document or environment compatibility checker should be improved.

[dmichon-msft]

We can probably get away with reverting the dependency on git 2.30 now that we are calling git merge-base manually, we'll just need to remove the --merge-base flag from the git diff-index call and document that the caller is responsible for calling git merge-base first or else they may get undesired behavior.

[Faithfinder]

There's also a question of "How far back can we go" - unless it's 2.20, or, even better, 2.11 - not much point in doing it. 2.25 would be no better than 2.30

[matthiasg]

2.25 is at least in standard apt install git.

Is there documentation somewhere why this change was made and what the merge-base command (when run manually) is protecting from ?