Using xubuntu 14.04 with proxy options set in /etc/environment, I search for a city for weather, but get no response. I have both HTTP_PROXY and http_proxy defined. Eg http_proxy=http://10.0.0.4:80 Wireshark shows the traffic, however it is somehow going to the wrong port! When I use port 80 in /etc/environment, the traffic ends up going to port 0; however if I specify any of several other ports, the traffic goes to the specified port on the proxy. So something special is going on when port 80 is specified. Note that many apps treat the default proxy port as 8080, so I am pretty much stuck with using an explicit port specification for this variable to be consistent with other apps.
I can't see any problem with the plugin code. It simply sets the proxy URI for libsoup. A quick search turned up this: http://upstream-tracker.org/changelogs/libsoup/2.45.92/changelog.html * Fixed problems with using an http proxy on port 80. [patch from Slava Monich on libsoup-list] Seems to be this commit: https://git.gnome.org/browse/libsoup/commit/?id=18ae820c81658b44e1ac7daf57df1ee0ef030d53 Seems to match your problem. Check your libsoup version and try to update it. Configuration issue, closing as invalid.
Confirmed -- the libsoup dependency was at fault. Tried the Xubuntu 14.10 version of the package (libsoup2.4-1_2.46.0-3) and removed/re-added the weather plugin from the panel to "encourage" the shared object to reload, and from there traffic went to the proxy as expected. This exposed another, previously hidden issue, in that I then received HTTP 404 errors back from the forecast server, apparently due to an obsolete URL. This issue was corrected by likewise upgrading xfce4-weather-plugin to the Xubuntu 14.10 version. (Fingers crossed that I didn't break anything else!) Thanks for getting me pointed in the right direction regarding libsoup.