Remove some non-determinism

[licaon-kter]

Your app is not built reproducible in F-Droid, but we continuously test older versions on https://verification.f-droid.org/ and would like more and more apps to become repro

Looking at the latest app report: https://verification.f-droid.org/packages/app.intra/

We can fix the GO BUILDID and the different /tmp paths.

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[licaon-kter]

Haha CLA, no, but you can take this as you please :wink:

[jyyi1]

Thanks for the contribution. But unfortunately this PR won't make the app reproducible. Because to ensure a reproducible build, we need to use a fixed version of gomobile, but they only officially provide the latest 0.0.0 version. This means that even if we fix the BUILDID, the produced binary isn't guaranteed to be reproducible.

[licaon-kter]

True, but I've tested this, and as the title says it's about "some" of it. :)

Could this be made perfect? I hope so, in the mean time, this PR improves things.

[licaon-kter]

As said, I won't submit to any CLA. :)

[ignoramous]

... to ensure a reproducible build, we need to use a fixed version of gomobile, but they only officially provide ... 0.0.0 ...

Also, gomobile driven builds don't yet respect -trimpath, at least not from what we've observed (from build of our Intra fork).

• https://github.com/golang/go/issues/40254