xvfb-run munges stdout and stderr together

[Robert Collins]

It executes the supplied command thusly:
DISPLAY=:$SERVERNUM XAUTHORITY=$AUTHFILE "$@" 2>&1

This should be
DISPLAY=:$SERVERNUM XAUTHORITY=$AUTHFILE "$@"

Leaving the caller to redirect stderr to stdout, or to supply a single fd at their discretion. The side effect of munging the two fd's together is that programs which provide structured data on stdout have their output streams corrupted if they, or any subprocesses they have, happen to write to stderr at an inopportune time.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Leon Blakey (thelq)]

Any updates? This still exists 4 years later in xvfb 2:1.16.4-1 . The only workaround is to copy the entire script locally and remove those 4 characters.

Also the package is xvfb, not xorg-server

[Timo Aaltonen (tjaalton)]

the source package is xorg-server

changing this would break a ton of autopkgtests that use xvfb-run which now get errors like:

testsuite FAIL stderr: QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to
             '/tmp/runtime-ubuntu'

[Launchpad Janitor (janitor)]

This bug was fixed in the package xorg-server - 2:1.19.4-1ubuntu2

---------------
xorg-server (2:1.19.4-1ubuntu2) artful; urgency=medium

  * xvfb-run: Keep redirecting stderr to stdout, autopkgtests need it.

 -- Timo Aaltonen <email address hidden> Wed, 11 Oct 2017 11:12:57 +0300

[Brad Isbell (brad-2)]

This bug is still present in xvfb 2:1.20.13-1ubuntu1~20.04.2. It prevents us from using `xvfb-run` when we need to disambiguate STDOUT and STDERR.

I'm not familiar with the problem of autopkgtests, but is this still an issue? Can autopkgtests be fixed?

If we're an impasse, does it make sense to turn this into a feature request to add a flag to change the redirection behavior?