Bug#860428: reprotest: use an existing HOME in the control build

[beuc at debian.org]

Package: reprotest
Version: 0.6
Severity: normal

Hi,

I was investigating why reprotest would report a reproducible build,
but still produce a different executable than when compiling directly.

After several tests (and then more) I eventually tracked it to HOME
being invariably non-existant in reprotest
(HOME=/nonexistent/first-build and HOME=/nonexistent/second-build),
while my normal compilation environment has an existing home (duh!).

This caused a subtle bug when cross-compiling with mingw and
wine-binfmt:

- existing home: ./configure attempts to run conftest.exe, wine can
  create '.wine', conftest.exe runs OK, configure assumes:
  checking whether we are cross compiling... no

- non-existing home: ./configure attempts to run conftest.exe, wine
  can't create '.wine', conftest.exe fails, configure assumes:
  checking whether we are cross compiling... yes

The respective binaries were very different notably due to a different
config.h.

(and now I understand why one should specify both --host *and* --build
when cross-compiling from autoconf ahah..)


To detect this issue, and probably others, I'd suggest making the
control build's HOME point to an existing directory.


Cheers!
Sylvain