== in cpanfile actually can freeze the dep. ZOMG. See https://gist.github.com/4688946 for plain local::lib without carton

gistfile1.txt

➜  perl -MTry::Tiny\ 1      
Try::Tiny version 1 required--this is only version 0.12.
BEGIN failed--compilation aborted.

➜  cat cpanfile
requires 'Try::Tiny', '== 0.11';

➜  carton -v
carton v0.9_7

➜  cpanm -V
cpanm (App::cpanminus) version 1.59_01

➜  carton install
Installing modules using cpanfile
Successfully installed Try-Tiny-0.11
1 distribution installed
Complete! Modules were installed into local

➜  carton exec -- perl -e 'use Try::Tiny 1'
Try::Tiny version 1 required--this is only version 0.11 at -e line 1.
BEGIN failed--compilation aborted at -e line 1.