[BRLTTY] BRLTTY Nix package

[Mario Lang]

Bram Duvigneau <bram at bramd.nl> writes:

> Mario Lang schreef op 7-5-2015 om 00:11:
>> Bram Duvigneau <bram at bramd.nl> writes:
>>
>>> to give the package a try, it should be available in the NixOS unstable
>>> channel and will be included in the next stable release.
>> Mind sharing the git repo and relevant paths?  I'd like to look at the
>> package definition.
>>
> Of course, any feedback is welcome.
>
> Package definition:
> https://github.com/NixOS/nixpkgs/blob/master/pkgs/tools/misc/brltty/default.nix

I found a problem when building this package on my Debian box.
However, I am not experienced enough with Nix to pinpoint exactly what
is responsible for that.  Let me describe:

/usr/lib/tcl8.6/tclConfig.sh on my system looks like this:
#! /bin/sh
. /usr/lib/`dpkg-architecture -qDEB_HOST_MULTIARCH`/tcl8.6/tclConfig.sh

Apparently, the nix build of brltty sources this script, which leads to
an infinite shell loop, since dpkg-architecture is not available in the
nix environment.  I know why this happens, but I am not sure what the
correct fix would be.  In any case, it seems to indicate that nix's
promise to only depend on things which come from nix itself is
definitely violated.  What is the correct fix?  Is it a patch to brltty
to not source this file from an absolute path?  Is it a problem of nix
itself?  Maybe you can shed a little light on this issue, any maybe
provide a fix as well?

-- 
CYa,
  ⡍⠁⠗⠊⠕