We are running opam with a custom repo [1] that includes an oclosure
package. Doing `opam install oclosure` fails immediately with:

The following actions will be performed:
 - install oclosure.0-dev
1 to install | 0 to reinstall | 0 to upgrade | 0 to downgrade | 0 to remove

=-=-= oclosure.0-dev =-=-=
The archive for oclosure.0-dev is in the local cache.
Extracting /Users/ashish/.opam/archives/oclosure.0-dev+opam.tar.gz
Build commands:
  configure --prefix /Users/ashish/.opam/system
  make
  make install
Uninstalling oclosure.0-dev
[WARNING] Command "rm -f" contains 1 space
The compilation of oclosure.0-dev failed in
/Users/ashish/.opam/system/build/oclosure.0-dev.

[ERROR] while installing oclosure.0-dev
= [RUN] "configure --prefix /Users/ashish/.opam/system"
= [CWD] "/Users/ashish/.opam/system/build/oclosure.0-dev"
... lots more environment variables printed

However, manually cd'ing
to /Users/ashish/.opam/system/build/oclosure.0-dev, then running the
configure, make, commands behaves differently. The configure succeeds. The
make runs for a while (but I did not let it run to completion). Question is
what is opam doing differently then running the commands manually? Is there
some way to see the error messages when opam install fails?

Also, note this failure happens on Mac OS X but the same repo succeeds for
us on CentOS and Ubuntu.

[1] https://github.com/smondet/opam-repository