Pjotr Prins <pjotr.public12@thebird.nl> writes:

> On Mon, Jul 25, 2016 at 08:13:33AM +0200, Ricardo Wurmus wrote:
>> > +   (native-inputs
>> > +    `(("patch" ,patch)
>> > +      ("patch/elixir-disable-failing-tests"
>> > +       ,(search-patch "elixir-disable-failing-tests.patch"))
>> > +      ("patch/elixir-disable-mix-tests"
>> > +       ,(search-patch "elixir-disable-mix-tests.patch"))))
>> 
>> This has been mentioned already and I’d like to move these to the
>> “source” field after identifying the reason why the build fails
>> otherwise.  I see that you’re doing this in order to patch after the
>> build phase.  Let’s see if this can be avoided.
>
> I tried and failed. Elixir people do not know either:
>
>   https://github.com/elixir-lang/elixir/issues/5043
>
> I think it is Mix magic. Probably tracking files in some way.

The reason seems to be that Elixir doesn’t compile files when the
timestamp is the epoch.  There is a staleness check before compilation.
When you patch files in a build phase their timestamps are changed, and
that leads to successful compilation.

To fix this when patching in the “source” expression I added a phase to
change the timestamps of all files to something more recent, recent
enough to also pass the staleness tests that check against a date of Jan
1, 2000.

>> Note we are talking a rather small minority of tests. 11 out of 2000+
>> for Elixir. For Mix 10% fails, mostly because of git. The Elixir
>> people wrote there should be no network access involved.

This one is weird and I haven’t been able to track it down.  During the
testing phase the “git_repo” fixture seems to be missing.  This causes
all the git tests to fail.  I don’t know at what point it is generated
and at what point it disappears, but I documented that this appears to
be the problem, so that it can be fixed at a later point.

>> > +diff --git a/lib/elixir/test/elixir/node_test.exs b/lib/elixir/test/elixir/node_test.exs
>> > +index d1f1fe6..5c2d469 100644
>> > +--- a/lib/elixir/test/elixir/node_test.exs
>> > ++++ b/lib/elixir/test/elixir/node_test.exs
>> > +@@ -6,8 +6,10 @@ defmodule NodeTest do
>> > +   doctest Node
>> > + 
>> > +   test "start/3 and stop/0" do
>> > +-    assert Node.stop == {:error, :not_found}
>> > +-    assert {:ok, _} = Node.start(:hello, :shortnames, 15000)
>> > +-    assert Node.stop() == :ok
>> > ++    IO.puts "Skipping test because GNU Guix does not allow the HOME environment variable."
>> > ++
>> > ++    # assert Node.stop == {:error, :not_found}
>> > ++    # assert {:ok, _} = Node.start(:hello, :shortnames, 15000)
>> > ++    # assert Node.stop() == :ok
>> > +   end
>> > + end
>> 
>> This was already addressed earlier.  We can probably just setenv HOME
>> before the tests.
>> 
>> Some of the remaining tests don’t seem to have any obvious fixes, so
>> I’ll get to them after making the above changes first.  Maybe the
>> failures disappear then.
>> 
>> Thanks again for the patch.  I hope you are willing to provide some
>> guidance when I have some problems understanding certain bits of the
>> build.
>
> I am happy to help out if you take the lead.

I documented the most common test errors, but there don’t seem to be any
quick fixes.  Attached is a new patch based on yours.  If this looks
good to you I’ll push it with you as the commit author and with a
“Co-authored-by: Ricardo Wurmus” line in the commit summary.

What do you think?

~~ Ricardo