unable to install ibm_db gem-Collection of common programming errors

ibm_db should be available in binary form on Windows, so you wouldn’t need to compile it yourself. You may need to explicitly specify the platform.

$ gem search -r ibm_db

*** REMOTE GEMS ***

ibm_db (2.5.17 ruby universal-darwin-13 x86-mingw32 x86_64-linux, 2.5.14 x86-linux, 2.5.11 x86-mswin32-60, 2.5.5 mswin32)

You probably want the x86-mingw32 binary.

I think the following command will install it:

gem install ibm_db --platform x86-mingw32

This should not require compilation.

(I can’t verify as I’m not currently on Windows.)