Can't install prebuilt gem

Question

I'm trying to install prebuilt binary of pg gem on windows (I don't want devkit):

>ruby -v
ruby 2.1.4p265 (2014-10-27 revision 48166) [x64-mingw32]

>gem install pg
Fetching: pg-0.17.1.gem (100%)
ERROR:  Error installing pg:
        The 'pg' native gem requires installed build tools.

>gem install pg -v 0.17.1 --platform=x64-mingw32
ERROR:  Error installing pg:
        The 'pg' native gem requires installed build tools.

even though the binary gem is published at https://rubygems.org/gems/pg/versions/0.17.1-x64-mingw32

What am I doing wrong ?

Same thing happens with 32-bit ruby.

Answer 1

So it turns out the gem was prebuilt for ruby 2.0.x which is not ABI compatible with ruby 2.1.x that I'm using. The error message could be more clear about that :(

Switched to the latest pre-release that contains needed binary and everything is fine now.