Currently building postgresql for Win32 with a mingw toolchain produces import libraries with *.a extension, whereas the extension should be *.dll.a. There are various downstream workarounds for this, see i.e. [1] and [2]. The attached patch 0001-Fix-import-library-extension.patch addresses this.
p, li { white-space: pre-wrap; }
Related, no actual static libraries are produced alongside the respective dlls. The attached patch 0002-Build-static-libraries.patch addresses this, in a similar fashion as is already done for the AIX case in Makefile.shlib.