So, one thought:
Instead of "staging" all of the dependencies and then modifying the makefile/.pro to look for the dependencies in six different places, it would be cleaner to configure with --prefix=<somewhere> and then 'make install' to put all the dependency libraries/include files in one spot. Ideally, none of the makefiles/.pro files would contain specific version numbers for anything.
Specific notes as I worked through doing that on a Windows system, putting dependencies in C:\deps :
Openssl: /bin/perl Configure --prefix=/c/deps mingw ...etc
BDB: ../dist/configure --prefix=/c/deps ...etc
Boost: b2.exe --layout=system --prefix=C:\deps link=static threading=multi runtime-link=static toolset=gcc ...etc
Qt: configure.exe -prefix=C:\deps -I "C:\deps\include" -L "C:\deps\lib" ...etc