Python.cmake is wrong about python-sip version

[antimirov]

Today I got this error after having upgraded my python-sip package to newer version:

"SIP is required in version 4.7 or later!"

But actually it's deeply wrong as my current version is 4.10. So I checked cmake/Python.cmake file in which I found that Cmake runs this command to compare current version of sip and to check whether it's bigger than 4.7:

$ python

import sip

print '%x' % sip.SIP_VERSION

So for older older version is: sip.SIP_VERSION=263945 hex=0x40709

For newer it's funny: sip.SIP_VERSION=264704 hex=40a00

So the newer version is lexicographically lower than the previous one. Looks like a bug.

[antimirov]

I'm sorry. Lexicographically 'a' is higher than "7", but the issue with Cmake's way of detecting python-sip version is still valid.

[borysiasty]

Did you try to remove the build/python directory before recompiling? I have SIP 4.10 and no such error occurs (Ubuntu). However, I can't find the version test you mention anywhere...

[wonder]

What QGIS version is that? This is not a problem anymore in SVN trunk (will be released as 1.5).

I think the development releases (v1.1 - v1.4) are affected, but there are no plans for further bugfix releases. So you might fix the problem manually in cmake/Python.cmake file:

Lines (153-155)

IF (SIP_VERSION EQUAL "${SIP_MIN_VERSION}" OR SIP_VERSION GREATER "${SIP_MIN_VERSION}")
  SET (SIP_IS_GOOD TRUE)
ENDIF (SIP_VERSION EQUAL "${SIP_MIN_VERSION}" OR SIP_VERSION GREATER "${SIP_MIN_VERSION}")

change to just

  SET (SIP_IS_GOOD TRUE)

[antimirov]

I fixed it with:

TRY_RUN_PYTHON (RES "print 40709" SIP_VERSION)

40709 is taken from older Ubuntu's python-sip.

2borysiasty: I have QGIS from ubuntugis-unstable PPA, I use it for latest GEOS and Qgis 1.4.

Thanks for the hint about 1.5, I see that SIP detection code was heavily rewritten there.