make: fix make install not using ldflags for git hash

[Kubuxu]

Resolves #3837

License: MIT
Signed-off-by: Jakub Sztandera kubuxu@protonmail.ch

[whyrusleeping]

@Kubuxu could we perhaps have a test for this?

[Kubuxu]

Not sure how to test it, it uses buildsystem and at the same time it installs into GOPATH, it would be hard.

[whyrusleeping]

A sharness test should be able to just check ipfs version --commit no?

[Kubuxu]

This affects make install not make build. We test for commit in docker tests, not sure if they run.

I will add test for commit, but it will find regression with build not install and I can already tell that it won't pass with coverage collection (as coverage doesn't insert this variable either).

[whyrusleeping]

@Kubuxu how about we default the variable to something that indicates its not an 'official' build?

[Kubuxu]

So do we want to confront Semver?

Then I suggest:
Official 0.4.8-rc1
Unofficial if not git var available 0.4.8-rc1+dirty.
With git: 0.4.8-rc1+git.a8b56d3ad

[whyrusleeping]

those SGTM. The 'sometag' is generally 'dirty'

[Kubuxu]

We can also add +dirty if there is git hash but there are local (not committed changes)

[whyrusleeping]

@Kubuxu is this ready to go?

[Kubuxu]

If tests are to be separate, yes.