[[!comment format=mdwn
 username="http://smcv.pseudorandom.co.uk/"
 nickname="smcv"
 subject="comment 1"
 date="2012-10-10T13:45:10Z"
 content="""
If your wiki configuration is written in YAML (it says IkiWiki::Setup::Yaml near the top), the correct syntax is something like

    ENV:
      http_proxy: http://proxy.uns.edu.ar:1280/
      https_proxy: http://proxy.uns.edu.ar:1280/

or

    ENV: { http_proxy: 'http://proxy.uns.edu.ar:1280/', https_proxy: 'http://proxy.uns.edu.ar:1280/' }

(many variations are possible, see <http://www.yaml.org/>).

The syntax you quoted is correct for Perl-syntax setup files (which will mention IkiWiki::Setup::Standard near the top), but not YAML ones.
"""]]