Support debug builds of terraform itself

[rbtcollins]

Quite likely an edge case, but I'm debugging a null pointer dereference in terraform (the shell itelf, not a particular provider). It would have been amazing to be able to say 'tfenv install --debug 1.6.1' and get a terraform binary that hasn't been stripped.

[Zordrak]

Do Hashicorp provide debug binaries? I've never seen such a thing provided by Hashicorp but I'm happy to be corrected.

[rbtcollins]

I don't know :)