commit f9a7ad4d332e4b61c02b4771e367c65d65bf4a1a Author: Damian Johnson atagar@torproject.org Date: Tue May 23 14:21:01 2017 -0700

Avoid KeyError in stem.util.system.is_available() when path unset

catalyst ran into testing errors where we made assertions that didn't hold for his system...

https://trac.torproject.org/projects/tor/ticket/22301

First gotcha I'm noticing is that is_available() raises an unexpected KeyError when we don't have a PATH environment variable...

====================================================================== ERROR: test_is_available ---------------------------------------------------------------------- Traceback (most recent call last): File "/home/atagar/Desktop/stem/test/integ/util/system.py", line 82, in test_is_available self.assertTrue(stem.util.system.is_available('ls')) File "/home/atagar/Desktop/stem/stem/util/system.py", line 251, in is_available cmd_exists = distutils.spawn.find_executable(command) is not None File "/usr/lib/python2.7/distutils/spawn.py", line 184, in find_executable path = os.environ['PATH'] File "/usr/lib/python2.7/UserDict.py", line 23, in __getitem__ raise KeyError(key) KeyError: 'PATH' --- stem/util/system.py | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/stem/util/system.py b/stem/util/system.py index 4b705f3..7b31516 100644 --- a/stem/util/system.py +++ b/stem/util/system.py @@ -247,6 +247,8 @@ def is_available(command, cached=True): return True elif cached and command in CMD_AVAILABLE_CACHE: return CMD_AVAILABLE_CACHE[command] + elif 'PATH' not in os.environ: + return False # lacking a path will cause find_executable() to internally fail else: cmd_exists = distutils.spawn.find_executable(command) is not None CMD_AVAILABLE_CACHE[command] = cmd_exists