[gdal-dev] The proj.dll mistery

[Frank Warmerdam]

Joaquim Luis wrote:
> Hi,
> 
> OK, I recovered from a  mysterious sudden stop working of my gdalwarp 
> and ogrproj MEX files. All I had were error messages like
> 
> "Failed to create coordinate transformation between the
> following coordinate systems.  This may be because they
> are not transformable, or because projection services
> (PROJ.4 DLL/.so) could not be loaded."
> 
> But not long ago those worked ok. It turn out that probably the culprit 
> was the "VantagePoint" here pointed out recently, that installed an 
> older (incompatible??) version of proj.dll on "C:\WINDOWS\system32"  (I 
> hate softs that do it).
> 
> When I have dll conflicts, I always use the Dependency Walker to help me 
> out, but in this case (an others??) the gdal.dll (trunk version) didn't 
> show up any dependency on proj.dll. So it was a matter of "and what if 
> it is in system32?" lucky guess that allowed me to solve the problem.
> There are plenty of dll dependencies on gdal.dll. Why not on proj.dll?

Joaquim,

For better or worse, many years ago I had the bright idea of making PROJ.DLL
(or libproj.so) demand loaded when needed so that it wouldn't be a "hard"
dependency of GDAL making it harder for people to get things built.  So
it does not show up as a dependency.  This is similar to how plugins are
handled.  They also won't show up.

It seems to me that the error message was pretty specific about what went
wrong.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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