telepresence: fix build

[MasseGuillaume]

setuptools-scm needs a full git repo in it's source to fetch the
version from the git tag

Motivation for this change

nix-env -f . -iA telepresence    
installing 'python3.8-telepresence-0.105'
these derivations will be built:
  /nix/store/hw8zqlgg65h2qcwa3i1wd568g395w2k3-sshuttle-0.78.5.drv
  /nix/store/l63g1kar8dp8xrqdkf0rw4lrf54w0q1c-python3.8-telepresence-0.105.drv
building '/nix/store/hw8zqlgg65h2qcwa3i1wd568g395w2k3-sshuttle-0.78.5.drv'...
Sourcing python-recompile-bytecode-hook.sh
Sourcing python-remove-tests-dir-hook
Sourcing python-catch-conflicts-hook.sh
Sourcing python-remove-bin-bytecode-hook.sh
Sourcing setuptools-build-hook
Using setuptoolsBuildPhase
Using setuptoolsShellHook
Sourcing pip-install-hook
Using pipInstallPhase
Sourcing python-imports-check-hook.sh
Using pythonImportsCheckPhase
Sourcing python-namespaces-hook
Sourcing setuptools-check-hook
Using setuptoolsCheckPhase
unpacking sources
unpacking source archive /nix/store/nb7kh6cl09hcvpsijlb2dlaymwslkfa7-source
source root is source
setting SOURCE_DATE_EPOCH to timestamp 315619200 of file source/tox.ini
patching sources
applying patch /nix/store/zhv3gyxd78kyfh6iyr2v408wbafp7d36-sudo.patch
patching file sshuttle/client.py
Hunk #1 succeeded at 185 with fuzz 1 (offset -7 lines).
configuring
no configure script, doing nothing
building
Executing setuptoolsBuildPhase
Traceback (most recent call last):
  File "nix_run_setup", line 8, in <module>
    exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\\r\\n', '\\n'), __file__, 'exec'))
  File "setup.py", line 29, in <module>
    setup(
  File "/nix/store/ld0khsbfx69hrvp4qfv3ijw0iczrkiyv-python3.8-setuptools-46.1.3/lib/python3.8/site-packages/setuptools/__init__.py", line 144, in setup
    return distutils.core.setup(**attrs)
  File "/nix/store/f87w21b91cws0wbsvyfn5vnlyv491czi-python3-3.8.3/lib/python3.8/distutils/core.py", line 108, in setup
    _setup_distribution = dist = klass(attrs)
  File "/nix/store/ld0khsbfx69hrvp4qfv3ijw0iczrkiyv-python3.8-setuptools-46.1.3/lib/python3.8/site-packages/setuptools/dist.py", line 425, in __init__
    _Distribution.__init__(self, {
  File "/nix/store/f87w21b91cws0wbsvyfn5vnlyv491czi-python3-3.8.3/lib/python3.8/distutils/dist.py", line 292, in __init__
    self.finalize_options()
  File "/nix/store/ld0khsbfx69hrvp4qfv3ijw0iczrkiyv-python3.8-setuptools-46.1.3/lib/python3.8/site-packages/setuptools/dist.py", line 717, in finalize_options
    ep(self)
  File "/nix/store/ld0khsbfx69hrvp4qfv3ijw0iczrkiyv-python3.8-setuptools-46.1.3/lib/python3.8/site-packages/setuptools/dist.py", line 724, in _finalize_setup_keywords
    ep.load()(self, ep.name, value)
  File "/nix/store/0p46jr9krabb9znd3zdwz3ia7639z22x-python3.8-setuptools_scm-4.1.2/lib/python3.8/site-packages/setuptools_scm/integration.py", line 17, in version_keyword
    dist.metadata.version = _get_version(config)
  File "/nix/store/0p46jr9krabb9znd3zdwz3ia7639z22x-python3.8-setuptools_scm-4.1.2/lib/python3.8/site-packages/setuptools_scm/__init__.py", line 148, in _get_version
    parsed_version = _do_parse(config)
  File "/nix/store/0p46jr9krabb9znd3zdwz3ia7639z22x-python3.8-setuptools_scm-4.1.2/lib/python3.8/site-packages/setuptools_scm/__init__.py", line 110, in _do_parse
    raise LookupError(
LookupError: setuptools-scm was unable to detect version for '/build/source'.

Make sure you're either building from a fully intact git repository or PyPI tarballs. Most other sources (such as GitHub's tarballs, a git checkout without the .git folder) don't contain the necessary metadata and will not work.

For example, if you're using pip, instead of https://github.com/user/proj/archive/master.zip use git+https://github.com/user/proj.git#egg=proj
builder for '/nix/store/hw8zqlgg65h2qcwa3i1wd568g395w2k3-sshuttle-0.78.5.drv' failed with exit code 1
cannot build derivation '/nix/store/l63g1kar8dp8xrqdkf0rw4lrf54w0q1c-python3.8-telepresence-0.105.drv': 1 dependencies couldn't be built
error: build of '/nix/store/l63g1kar8dp8xrqdkf0rw4lrf54w0q1c-python3.8-telepresence-0.105.drv' failed

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[flokli]

Also, please make 2 commits, one fixing the build, and one to bump the version.

[flokli]

You should be able to just add a

preBuild = ''
  export SETUPTOOLS_SCM_PRETEND_VERSION="${version}"
'';

[Mic92]

Result of nixpkgs-review pr 92743 1

1 package built:

- telepresence