I have successfully built GDAL 1.5.0 Perl binding on Cygwin and the followings might be helpful for those who experience problems.

1. Go to directory gdal-1.5.0/swig/perl and run 'perl Makefile.PL'.  The following four Makefiles should be created if it succeeds:
{{{
Makefile_Geo__GDAL
Makefile_Geo__GDAL__Const
Makefile_Geo__OGR
Makefile_Geo__OSR
}}}
2. Edit each of the four Makefiles by appending `-lstdc++` after each `-lgdal` and save them.

3. Run make using each of the four Makefiles as follows:
{{{
make -f Makefile_Geo__GDAL
make -f Makefile_Geo__GDAL__Const
make -f Makefile_Geo__OGR
make -f Makefile_Geo__OSR
}}}
4. Install the Perl `Geo::GDAL` package by running
{{{
make -f Makefile_Geo__GDAL install
}}}

That's it. Enjoy!

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Source:
 * http://www.nabble.com/GDAL-1.5.0-Perl-Binding-on-Cygwin-td14960908.html