Download this https://github.com/trinityrnaseq/trinityrnaseq/releases/tag/Trinity-v2.6.6
➜ cd trinityrnaseq-Trinity-v2.6.6
➜ trinityrnaseq-Trinity-v2.6.6 git:(master) ✗ make
Using gnu compiler for Inchworm and Chrysalis
cd Inchworm && (test -e configure || autoreconf) \
...