vcstools: fix dependencies

missing setuptools

```
$ ./results/vcstool/bin/vcs --help
Traceback (most recent call last):
  File "/nix/store/m9w0gapwnwffhnvyv3ds14mgbx2p5y93-vcstool-0.2.7/bin/.vcs-wrapped", line 6, in <module>
    from vcstool.commands.vcs import main
  File "/nix/store/m9w0gapwnwffhnvyv3ds14mgbx2p5y93-vcstool-0.2.7/lib/python3.7/site-packages/vcstool/commands/vcs.py", line 5, in <module>
    from vcstool.commands.help import get_entrypoint
  File "/nix/store/m9w0gapwnwffhnvyv3ds14mgbx2p5y93-vcstool-0.2.7/lib/python3.7/site-packages/vcstool/commands/help.py", line 6, in <module>
    from pkg_resources import load_entry_point
ModuleNotFoundError: No module named 'pkg_resources'
```

1 files changed, 1 insertions, 1 deletions

diff --git a/pkgs/development/tools/vcstool/default.nix b/pkgs/development/tools/vcstool/default.nix
index f67bcb29966de..bab3ebd57573f 100644
--- a/pkgs/development/tools/vcstool/default.nix
+++ b/pkgs/development/tools/vcstool/default.nix
@@ -12,7 +12,7 @@ buildPythonApplication rec {
     sha256 = "1mq8lmb1wh55cqdj7javq7qia4217h6vf5ljc99gsjyibi7g7d3k";
   };
 
-  propagatedBuildInputs = [ pyyaml ];
+  propagatedBuildInputs = [ pyyaml setuptools ];
 
   makeWrapperArgs = ["--prefix" "PATH" ":" (stdenv.lib.makeBinPath [ git bazaar subversion ])];