1082980 - Running mach robocop without MOZ_HOST_BIN set fails with an unfriendly error

Status: RESOLVED DUPLICATE of bug 1126057

(Testing :: Mochitest, defect)

Description

[Mike Hommey [:glandium]]

Error running mach:

    ['robocop']

The error occurred in the implementation of the invoked mach command.

This should never occur and is likely a bug in the implementation of that
command. Consider filing a bug for this issue.

If filing a bug, please include the full output of mach, including this error
message.

The details of the failure are as follows:

TypeError: coercing to Unicode: need string or buffer, NoneType found

  File "/home/glandium/mozilla-central/testing/mochitest/mach_commands.py", line 887, in run_robocop
    '--xre-path=' + os.environ.get('MOZ_HOST_BIN'),

Comment 1

[Geoff Brown [:gbrown]]

The make target still provides friendly messages:

gbrown@mozpad:~/objdirs/droid$ export MOZ_HOST_BIN=
gbrown@mozpad:~/objdirs/droid$ make mochitest-robocop
environment variable MOZ_HOST_BIN must be set to a directory containing host xpcshell

gbrown@mozpad:~/objdirs/droid$ export MOZ_HOST_BIN=junk
gbrown@mozpad:~/objdirs/droid$ make mochitest-robocop
MOZ_HOST_BIN does not specify a directory

gbrown@mozpad:~/objdirs/droid$ export MOZ_HOST_BIN=/home/gbrown
gbrown@mozpad:~/objdirs/droid$ make mochitest-robocop
xpcshell not found in MOZ_HOST_BIN

It would be nice if mach did the same.