Hello all,
I was trying to install mod_openid in Zotonic 0.8.1 with no success:

[ivanmr@localhost zotonic-0.8.1]$ bin/zotonic installmodule mod_openid
Getting module index
** Installing mod_openid ...
*sh: hg: command not found*
** mod_openid OK
cd deps/iconv && ./rebar compile
deps/z_logger/Makefile
make[1]: Entering directory
`/home/ivanmr/Documents/instalaciones/zotonic-0.8.1/deps/z_logger'
make[1]: Leaving directory
`/home/ivanmr/Documents/instalaciones/zotonic-0.8.1/deps/z_logger'
deps/gen_smtp/Makefile
make[1]: Entering directory
`/home/ivanmr/Documents/instalaciones/zotonic-0.8.1/deps/gen_smtp'
==> iconv (compile)
==> gen_smtp (compile)
make[1]: Leaving directory
`/home/ivanmr/Documents/instalaciones/zotonic-0.8.1/deps/gen_smtp'
deps/webzmachine/Makefile
make[1]: Entering directory
`/home/ivanmr/Documents/instalaciones/zotonic-0.8.1/deps/webzmachine'
==> webzmachine (get-deps)
==> webzmachine (compile)
make[1]: Leaving directory
`/home/ivanmr/Documents/instalaciones/zotonic-0.8.1/deps/webzmachine'
deps/mochiweb/Makefile
make[1]: Entering directory
`/home/ivanmr/Documents/instalaciones/zotonic-0.8.1/deps/mochiweb'
==> mochiweb (get-deps)
==> mochiweb (compile)
make[1]: Leaving directory
`/home/ivanmr/Documents/instalaciones/zotonic-0.8.1/deps/mochiweb'
deps/lager/Makefile
make[1]: Entering directory
`/home/ivanmr/Documents/instalaciones/zotonic-0.8.1/deps/lager'
./rebar get-deps
./rebar compile
==> lager (compile)
==> lager (get-deps)
make[1]: Leaving directory
`/home/ivanmr/Documents/instalaciones/zotonic-0.8.1/deps/lager'
modules/mod_oauth/Makefile
make[1]: Entering directory
`/home/ivanmr/Documents/instalaciones/zotonic-0.8.1/modules/mod_oauth'
make -C deps/erlang-oauth
make[2]: Entering directory
`/home/ivanmr/Documents/instalaciones/zotonic-0.8.1/modules/mod_oauth/deps/ erlang-oauth'
make[2]: Leaving directory
`/home/ivanmr/Documents/instalaciones/zotonic-0.8.1/modules/mod_oauth/deps/ erlang-oauth'
make[1]: Leaving directory
`/home/ivanmr/Documents/instalaciones/zotonic-0.8.1/modules/mod_oauth'
Updating zotonic zotonic001
Update:'zotonic...@localhost.localdomain'
There is no node with this name

I couldn't see what was wrong until I noticed the third output line, "*sh:
hg: command not found*". I found this means I don't have Mercurial
installed. Shouldn't the installation stop right here?. The fact it
continues doing things and producing output lines makes it difficult to
find where it failed.

Cheers,
Ivan Martinez