Dia crashing with Mac OS 10.11.6

Issue: Since "upgrading" to El Capitan, Dia won't open (icon briefly appears then vanishes).

Error message (when opening via commandline):

(process:45300): Gdk-WARNING **: locale not supported by C library

(process:45300): Gtk-WARNING **: Locale not supported by C library.
    Using the fallback 'C' locale.

(dia-bin:45300): Gtk-WARNING **: cannot open display: /private/tmp/com.apple.launchd.xxxxxxx/org.macosforge.xquartz:0

Followed instruction on this bug report: https://sourceforge.net/p/dia-installer/support-requests/105/ without success:

Error message following code change suggested in bug report:

(process:44516): Gdk-WARNING **: locale not supported by C library

(process:44516): Gtk-WARNING **: Locale not supported by C library.
    Using the fallback 'C' locale.

(dia-bin:44516): Gtk-WARNING **: cannot open display: :0

Relevant Version Information:

Dia version 0.97.2 (freshly downloaded from http://dia-installer.de/download/macosx.html)
XQuartz 2.7.11
Mac OS 10.11.6

Has anyone managed to get Dia working with El Capitan?

Solution

In case this helps anyone else, a fresh install of XQuartz (https://www.xquartz.org) resolved the issue.

Note: still needed the export DISPLAY=:0 addition at line 39 in the source code.