Re: [PATCH 1/7] gitlab-ci: speed up installation of Git for Windows SDK

[Patrick Steinhardt <ps@pks.im>]

On Fri, Nov 06, 2026 at 09:20:57AM -0800, Junio C Hamano wrote:
> Patrick Steinhardt <ps@pks.im> writes:
> 
> > The "build:mingw64" job on GitLab CI downloads the minimal Git for
> > Windows SDK on every run and then extracts it via `Expand-Archive`,
> > which is expensive.
> >
> > Improve this by caching the SDK and by using tar(1) instead of
> > `Expand-Archive`.
> > Note that caching actually only gives us a win of a
> > couple seconds. The bigger win here is using tar(1), which speeds up
> > extracting the archive from 3 minutes to about 10 seconds. Regardless of
> 
> Wow, is a tool to move the bits from one part of a rusted iron
> surface to another part really so much more expensive compared to
> another tool to move the same bits, to make a difference that is
> worth doing this?

I was surprised by this, as well.

> > that though, caching the SDK feels like a sensible thing to do as it
> > removes one step that may spuriously fail.
> 
> One thing that may make readers curious is if we need to worry about
> this cached copy going stale.

Yes, it may go stale, but I'm not even sure whether that really matters.
I decided to just do this as-is and Cc Johannes to maybe facilitate his
input on this part. But arguably, we can just skip the cache altogether
as it didn't really buy much anyway.

> > diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
> > index 9b7698a0037..15419a954b3 100644
> > --- a/.gitlab-ci.yml
> > +++ b/.gitlab-ci.yml
> > @@ -127,9 +127,16 @@ build:mingw64:
> >      - saas-windows-medium-amd64
> >    variables:
> >      NO_PERL: 1
> > +  cache:
> > +    key:
> > +      files:
> > +        - ci/install-sdk.ps1
> > +        - ci/install-dependencies.ps1
> > +    paths:
> > +      - .dependencies
> >    before_script:
> >      - *windows_before_script
> > -    - ./ci/install-sdk.ps1 -directory "git-sdk"
> > +    - ./ci/install-sdk.ps1 -Directory "git-sdk"
> 
> Is this change essential to understand this patch, or is it an
> unrelated general clean-up to follow some style rules?  I notice
> that ...
> 
> >      - ./ci/install-dependencies.ps1 -Mingw
> >    script:
> >      # The minimal SDK's profile resets PATH.
> > diff --git a/ci/install-sdk.ps1 b/ci/install-sdk.ps1
> > index 66f24838a40..1dbcef04a18 100755
> > --- a/ci/install-sdk.ps1
> > +++ b/ci/install-sdk.ps1
> > @@ -1,12 +1,26 @@
> >  param(
> > -    [string]$directory='git-sdk',
> > -    [string]$url='https://github.com/git-for-windows/git-sdk-64/releases/download/ci-artifacts/git-sdk-x86_64-minimal.zip'
> > +    [string]$Directory='git-sdk',
> > +    [string]$URL='https://github.com/git-for-windows/git-sdk-64/releases/download/ci-artifacts/git-sdk-x86_64-minimal.zip',
> > +    [string]$DownloadDirectory='.dependencies'
> 
> ... we are making a matching change here to upcase the parameter
> names here.

Well, with the new DownloadDirectory parameter everything else would
have been inconsistent, so I made those changes while at it. I'll dropt
he cache in v2 though, and with that we can drop these changes, too.

Patrick