Hi,

When building ffmpeg-4.2.2 (current master, 8d1b22b27fba3d1e4310f02a5897d231b42ca117)
natively on 32bit hardware, the build fails because of two failing tests
(full log attached)

--8<---------------cut here---------------start------------->8---
--- ./tests/ref/fate/filter-pixdesc-grayf32be	2019-12-31 21:35:25.000000000 +0000
+++ tests/data/fate/filter-pixdesc-grayf32be	2020-02-22 15:15:50.209912771 +0000
@@ -1 +1 @@
-pixdesc-grayf32be   9b23c74e8e8ffae5d7c7e82bbf5929da
+pixdesc-grayf32be   01816b882016239d0cf84241818926a4
--- ./tests/ref/fate/filter-pixdesc-grayf32le	2019-12-31 21:35:25.000000000 +0000
+++ tests/data/fate/filter-pixdesc-grayf32le	2020-02-22 15:15:50.253914049 +0000
@@ -1 +1 @@
-pixdesc-grayf32le   291f074a24c44799a1f437d1c55556f1
+pixdesc-grayf32le   1b234318d06d5a76e980c376ad8764e5
Test filter-pixdesc-grayf32be failed. Look at tests/data/fate/filter-pixdesc-grayf32be.err for details.
make: *** [tests/Makefile:238: fate-filter-pixdesc-grayf32be] Error 1
make: *** Waiting for unfinished jobs....
Test filter-pixdesc-grayf32le failed. Look at tests/data/fate/filter-pixdesc-grayf32le.err for details.
make: *** [tests/Makefile:238: fate-filter-pixdesc-grayf32le] Error 1

Test suite failed, dumping logs.
command "make" "fate" "-j" "2" failed with status 2
--8<---------------cut here---------------end--------------->8---

How to attempt fixing this?

Building it on 64 bit hardware (much faster!) works for me, i.e. this

    guix build --system=i686-linux ffmpeg

works for me and can be used as a substitute...

Together with qemu-minimal-2.10 depending on ffmpeg
(https://bugs.gnu.org/39737) and no available substitutes this made for
a pretty rough "guix system reconfigure"-experience today.

I worked around this by adding a ffmpeg package that ignored the check
phase (#:tests? #f); I am wondering if we could we enable (something
like) that from the command line?  WDYT?

Apart from this hiccup I had a smooth upgrade from guix 0.14,
impressive!

Greetings,
janneke