After switching to Ubuntu 11.04 from Fedora 15 I noticed that I wasn’t able to connect to our internal Citrix environment using ICAClient. Having followed the usual documentation (listed below) I was presented with the following:

*** glibc detected *** /usr/lib/ICAClient/wfica: free(): invalid next size (fast): 0x09c6e8b0 ***
      ======= Backtrace: =========
      ...
The process is actually core-dumping in libproxy.so:

Program terminated with signal 11, Segmentation fault.
      #0  0xf70d8f72 in nbc_connect () from /usr/lib/ICAClient/libproxy.so
      (gdb) bt
      #0  0xf70d8f72 in nbc_connect () from /usr/lib/ICAClient/libproxy.so
      #1  0xf70cd4d6 in NullConnect () from /usr/lib/ICAClient/libproxy.so
      #2  0xf70ce6cd in ProxyConnect () from /usr/lib/ICAClient/libproxy.so
      #3  0xf70ce8b1 in PROXYconnect () from /usr/lib/ICAClient/libproxy.so
      #4  0xf70d8764 in IPSTACKconnect () from /usr/lib/ICAClient/libproxy.so
      #5  0x080c3757 in ?? ()
      #6  0x080c2518 in ?? ()
      #7  0xf70c094a in ?? () from /usr/lib/ICAClient/PDCRYPT1.DLL
      #8  0x080c060a in WdSetInformation ()
      #9  0x080ffd8a in wdConnect ()
      #10 0x08100f9b in NCSbind ()
      #11 0x08077d09 in OldMain ()
      #12 0x08137f4a in PlatAppMain ()
      #13 0x080feda6 in AppMain ()
      #14 0x08137eda in main ()

However, Library dependencies on the libproxy.so looked fine:

$ ldd /usr/lib/ICAClient/libproxy.so
      linux-gate.so.1 =>  (0xf7732000)
      libc.so.6 => /lib32/libc.so.6 (0xf7594000)
      /lib/ld-linux.so.2 (0xf7733000)

In the strace output I could see it was trying to parse a proxy configuration – having already unset all proxy variables (http_proxy, https_proxy, ftp_proxy) I was wondering where he was trying to get the proxy configuration from. The following line was the important one:

[pid 15818] open("/home/i064850/.mozilla/firefox/cuqn88q3.default/prefs.js", O_RDONLY) = 5

It was actually trying to get my proxy configuration from my Firefox Preferences! While one could argue about this decision, it seems to cause my issue – because after moving the .mozilla folder, wfica was finally able to connect!

In the end I found out that this is an issue if you use Automatic Proxy Configuration in Firefox together with the Citrix ICA Client. Once you either deactivate or manually specify the proxy setting, it magically works.

I still have to find out where to submit a bug report for ICAClient – probably nowhere …

[Edit] Bug report posted

References: The Ubuntu ICAClient HowTo