poor error reporting when a dependency can't be imported: Warning: version number None found for dependency 'pyopenssl' (imported from None) could not be parsed.

[davidsarah]

The message from the import exception is preserved and printed, which is good, but the reference to a version number of None is spurious. The code that prints this message is in src/allmydata/__init__.py​.

[david-sarah@…]

In 36c176224d1ebacf:

(The changeset message doesn't reference this ticket)

[davidsarah]

The user who brought this to my attention confirmed that this fixes the error report:

Warning: dependency 'pyopenssl' could not be imported. pkg_resources thought it should be possible to import version '0.11' from '/home/jonathan/allmydata-tahoe-1.9.2/support/lib/python2.6/site-packages/pyOpenSSL-0.11-py2.6-linux-i686.egg'.
The exception trace was (<type 'exceptions.ImportError'>, 'libssl.so.0.9.8: cannot open shared object file: No such file or directory', ('/home/jonathan/allmydata-tahoe-1.9.2/support/lib/python2.6/site-packages/pyOpenSSL-0.11-py2.6-linux-i686.egg/OpenSSL/__init__.py', 40, '<module>', 'from OpenSSL import crypto')).

and I also checked that it doesn't break a normal installation.

Post-commit review of 36c176224d1ebacf would be useful.

[zooko]

Reviewed 36c176224d1ebacf. Looks good to me!

[david-sarah <david-sarah@…>]

In 36c176224d1ebacf:

src/allmydata/init.py: ensure that if a dependency cannot be imported, we will report that rather than reporting a confusing message about the version and location being None. fixes #1804