I still feel like it should apply, this is the first term of the gpl:

This License applies to any program or other work which contains a notice placed by the copyright holder saying it may be distributed under the terms of this General Public License. The "Program", below, refers to any such program or work, and a "work based on the Program" means either the Program or any derivative work under copyright law: that is to say, a work containing the Program or a portion of it, either verbatim or with modifications and/or translated into another language

"I rewrote it in another language as a library instead of an exe" is still covered under this term isn't it?