Display exit code with InvocationErrors

[pytoxbot]

• Bitbucket: https://bitbucket.org/hpk42/tox/issue/290
• Originally reported by: @blueyed
• Originally created at: 2015-11-25T13:57:56.481

When a command fails, you currently only get ERROR: InvocationError: '/usr/bin/false', but the exitcode itself is useful/important, e.g. with
py.test using 5 for "no tests collected".

The following patch would provide that, by using a custom __str__ method for
InvocationError - but it does not handle the case where that might be missing (not all instances / calls to it provide it).

Maybe a custom __init__ should be used to set the arguments as properties explicitly, and then use them?!

diff -r e9569646da4f tox/__init__.py
--- a/tox/__init__.py   Wed Nov 25 12:27:48 2015 +0100
+++ b/tox/__init__.py   Wed Nov 25 13:23:26 2015 +0100
@@ -17,6 +17,9 @@
         "signals that an interpreter could not be found"
     class InvocationError(Error):
         """ an error while invoking a script. """
+        def __str__(self):
+            return "%s: %s (exitcode %d)" % (self.__class__.__name__,
+                                             self.args[0], self.args[1])
     class MissingFile(Error):
         """ an error while invoking a script. """
     class MissingDirectory(Error):

This is related / similar to #192.

[pytoxbot]

Original comment by @The-Compiler

+1 for this feature - I've had tests segfault and no useful info from tox before. I got used to it, but the first time I saw it it took me a while to figure out what happened.

[pytoxbot]

Original comment by @hpk42

if you can provide a test and put this all into a PR i'll see to merge it.

[pytoxbot]

Original comment by @blueyed

Here is an updated patch that will pass tests at least:

--- a/tox/__init__.py   Wed Nov 25 12:27:48 2015 +0100
+++ b/tox/__init__.py   Wed Nov 25 18:37:41 2015 +0100
@@ -17,6 +17,20 @@
         "signals that an interpreter could not be found"
     class InvocationError(Error):
         """ an error while invoking a script. """
+        def __init__(self, *args):
+            super(exception.Error, self).__init__(*args)
+            self.command = args[0]
+            try:
+                self.exitcode = args[1]
+            except IndexError:
+                self.exitcode = None
+
+        def __str__(self):
+            if self.exitcode:
+                return "%s: %s (exitcode %d)" % (self.__class__.__name__,
+                                                 self.command, self.exitcode)
+            return "%s: %s" % (self.__class__.__name__, self.command)
+
     class MissingFile(Error):
         """ an error while invoking a script. """
     class MissingDirectory(Error):

[pytoxbot]

Original comment by @blueyed

While at it, it might be useful to display it also here:

diff -r e9569646da4f tox/venv.py
--- a/tox/venv.py   Wed Nov 25 12:27:48 2015 +0100
+++ b/tox/venv.py   Wed Nov 25 14:50:51 2015 +0100
@@ -137,6 +137,7 @@
             return sys.exc_info()[1]
         try:
             self.install_deps(action)
+        # TODO: display InvocationError here?
         except tox.exception.InvocationError:
             v = sys.exc_info()[1]
             return "could not install deps %s; v = %r" % (

[obestwalter]

@blueyed - still interested to make this happen?

[blueyed]

@obestwalter
In general, yes - but not in the near future.
Feel free to pick up the patch(es) from here, of course.

[obestwalter]

@blueyed thanks - I might try to crystalize your drops of genius in this issue in a PR then :)

[ederag]

This is useful, thanks !
The patch #290 (comment) did not apply to current repo. Here is an updated one (only the @@ line changed).

diff --git a/tox/__init__.py b/tox/__init__.py
index b7a1631..d872b32 100644
--- a/tox/__init__.py
+++ b/tox/__init__.py
@@ -34,6 +34,19 @@ class exception:
 
     class InvocationError(Error):
         """ an error while invoking a script. """
+        def __init__(self, *args):
+            super(exception.Error, self).__init__(*args)
+            self.command = args[0]
+            try:
+                self.exitcode = args[1]
+            except IndexError:
+                self.exitcode = None
+
+        def __str__(self):
+            if self.exitcode:
+                return "%s: %s (exitcode %d)" % (self.__class__.__name__,
+                                                 self.command, self.exitcode)
+            return "%s: %s" % (self.__class__.__name__, self.command)
 
     class MissingFile(Error):
         """ an error while invoking a script. """