Non-deterministic package IDs are really bad in 7.10

Mateusz Kowalczyk fuuzetsu at
Wed May 20 18:01:26 UTC 2015

On 05/19/2015 08:33 AM, Joachim Breitner wrote:
> Hi,
> Am Dienstag, den 19.05.2015, 07:27 +0100 schrieb Mateusz Kowalczyk:
>> On 05/19/2015 06:46 AM, Daniel Peebles wrote:
>>> Don't Nix builds all happen in a randomly generated temporary directory by
>>> default? Then you just copy to $out in installPhase. Perhaps stabilizing
>>> the build directory would help alleviate some of the immediate problems, if
>>> what Joachim is describing affects us too.
>> Oh, I was far too hasty in reading the bug on the Debian tracker. Yes, I
>> suppose this could be a problem for us though I'd like to see it first
>> before trying to work around it.
> it’s easy to check: Just run
> $ ghc --show-iface /usr/lib/ghc/base-|grep Dep
> addDependentFile "/build/ghc-LIQtDg/ghc-7.8.4/includes/ghcplatform.h"
> addDependentFile "libraries/base/dist-install/build/autogen/cabal_macros.h"
> addDependentFile "/usr/include/stdc-predef.h"

Seems we're good?:

[nix-shell:~]$ ghc --show-iface
 | grep Dep
addDependentFile "libraries/base/dist-install/build/autogen/cabal_macros.h"

With our new architecture using 7.10.1:

[nix-shell:~]$ ghc --show-iface
| grep Dep
addDependentFile "libraries/base/dist-install/build/autogen/cabal_macros.h"

> If you see the build path appearing there, you are affected by the bug.

In light of above, I don't know if I should be happy because we don't
seem to be affected or scared that it's just subtle and will bite us

> Greetings,
> Joachim
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Mateusz K.

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