[netcdf-porting] Problem building netcdf-4.3.3.1 (mingw)

Hi,
I'm trying to build netcdf-4.3.3.1 using mingw compiler (gcc-4.9.2) in the msys shell, but configure terminates with: 

.....
checking for library containing deflate... -lz
checking for floor in -lm... yes
checking for dlfcn.h... (cached) no
configure: error: Cannot find dlfcn.h, yet --enable-dynamic-loading was used.
What is that all about ? I didn't specify "--enable-dynamic-loading" anywhere, and it's not even a valid configure option.
The configure args I've used are "--disable-shared --enable-static --enable-netcdf-4". 

Gzipped config.log (config.log.gz) is attached.
I had no problems building 4.3.2 using the same compiler, same msys shell, same configure command ... same everything.
In case it helps, I'm also attaching a gzipped 4.3.2 config.log (as config_432.log.gz) 

Any help would be much appreciated.

Cheers,
Rob

Attachment: config.log.gz
Description: GNU Zip compressed data

Attachment: config_432.log.gz
Description: GNU Zip compressed data