Re: Testing isolated builds

[Pjotr Prins]

On Wed, Sep 20, 2017 at 02:18:01PM +0200, Pjotr Prins wrote:
> I am facing some issues try to upgrade Elixir. The problem is that the
> build fails on tests, but when I build by hand inside
> /tmp/guix-build-elixir-1.5.1.drv-0/ the build passes.
> 
> Is there an easy way to create a similarly restricted environment when
> doing a build outside Guix? I.e., no $HOME, no /tmp access, no
> network? Any hints on an approach?

When I build with Guix I get an error 

       test/elixir/kernel/dialyzer_test.exs:95
       ** (File.CopyError) could not copy from 
"/tmp/guix-build-elixir-1.5.1.drv-0/elixir-1.5.1/lib/elixir/tmp/dialyzer/Elixir.Dialyzer.ForBooleanCheck.beam"
 to 
"/tmp/guix-build-elixir-1.5.1.drv-0/elixir-1.5.1/lib/elixir/tmp/dialyzer/line95/Elixir.Dialyzer.ForBooleanCheck.beam":
 no such file or directory
       code: copy_beam! context, Dialyzer.ForBooleanCheck
       stacktrace:
         (elixir) lib/file.ex:631: File.cp!/3
         test/elixir/kernel/dialyzer_test.exs:96: (test)


When I try:

  ./pre-inst-env guix environment erlang -C --ad-hoc erlang vim make \
    glibc-utf8-locales git --pure \
    --share=/tmp/guix-build-elixir-1.5.1.drv-12

That gives me a clean environment, but now all effing tests pass!

The Guix build environment does not create
/tmp/guix-build-elixir-1.5.1.drv-0/elixir-1.5.1/lib/elixir/tmp for some reason.
Because when then test fails it does not exist. The 
Elixir.Dialyzer.ForBooleanCheck.beam is never created.

It is weird.

Could it be file permissions? I think mkdir_p would throw a descriptive error 
if it fails. 

If no one has an idea here I'll try and plug in informative errors. But it is a
royal pain I can't reproduce the error in guix environment.

Pj.
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