Connection error when no client-platform (drivers) installed is confusing

[Robert Ancell]

If you don't have a client-platform installed the error message during connection implies the Mir socket is missing, i.e.

$ mir_demo_client_basic -m /tmp/mir_socket
Failed to connect to server `/tmp/mir_socket': No such file or directory

I'd expect error messages like:
Failed to connect to server `/tmp/mir_socket': Unable to open Mir socket (No such file or directory)
Failed to connect to server `/tmp/mir_socket': Unable to access client platform (No such file or directory)

[Daniel van Vugt (vanvugt)]

See also similar bug 1381398.

[Daniel van Vugt (vanvugt)]

Come to think of it, failure to find any graphics drivers should be logged at least with Error severity, so should pop up on the client's stderr ideally.

[Daniel van Vugt (vanvugt)]

Turns out we do have a better error message if the client-modules directory is empty:
   Failed to connect to server `/tmp/mir_socket': Attempted to create a ClientPlatformFactory with no platform modules

But if the directory is missing, it's too cryptic:
   Failed to connect to server `/tmp/mir_socket': No such file or directory

[PS Jenkins bot (ps-jenkins)]

Fix committed into lp:mir at revision None, scheduled for release in mir, milestone 0.15.0

[Launchpad Janitor (janitor)]

This bug was fixed in the package mir - 0.15.0+15.10.20150818-0ubuntu1

---------------
mir (0.15.0+15.10.20150818-0ubuntu1) wily; urgency=medium

  [ Daniel van Vugt ]
  * New upstream release 0.15.0 (https://launchpad.net/mir/+milestone/0.15.0)
    - ABI summary: Only servers and graphics drivers need rebuilding;
      . Mirclient ABI unchanged at 9
      . Mirserver ABI bumped to 33
      . Mircommon ABI unchanged at 5
      . Mirplatform ABI bumped to 9
    - Enhancements:
      . Add support for Mir-on-X11.
      . Latency reduction optimizations (around ~15ms reduction in total):
        Reduced input event resampling latency by 5ms. Reduced output latency
        (in system compositors) by around 10ms with the introduction of
        "predictive bypass". And we're not finished; future Mir releases
        should reduce latency further.
      . Introduced a python3-based Mir performance framework.
      . Lots of preparation for an architectural overhaul of buffer swapping,
        required in the least to support future optimizations like nested
        bypass.
      . Added a new cursor: crosshair
      . Added support for 15/16-bit client pixel formats ("high colour").
      . Added a new client function to make picking the right pixel format
        for a given EGLConfig super simple: mir_connection_get_egl_pixel_format
      . Added application-not-responding detection
      . Added client API for specifying input region shape.
      . Fixed the remaining threading flaws identified by ThreadSanitizer and
        turned it on permanently for all continuous integration in future.
      . Added support for relative pointer motion events (e.g. for gaming).
    - Bug fixes:
      . Fix focus issues breaking autopilot tests entering text (LP: #1468029)
      . Fix mir tests failure on armhf with GCC5 (LP: #1478213)
      . mir_buffer_stream_swap_buffers_sync can hang constraints (LP: #1479899)
      . Loading libmirclient.so twice leads to a segfault in libmirprotobuf.so
        (LP: #1391976)
      . Visible corruption in SDL apps (LP: #1460149)
      . MultiThreadedCompositor::destroy_compositing_threads hangs/deadlocks on
        shutdown or display reconfiguration (LP: #1471909)
      . ctest/"make test" reports 100% tests pass even when some fail.
        (LP: #1472911)
      . Mir server crashed - GLib-CRITICAL **: g_source_get_context: assertion
       'source->context != NULL || !SOURCE_DESTROYED (source)' failed
        (LP: #1473869)
      . USC crash on multimonitor unplug [std::exception::what: error during
        hwc prepare()] (LP: #1474891)
      . [regression] Input focus delay after switching app back into focus
        (LP: #1480654)
      . GLibMainLoopTest.propagates_exception_from_server_action fails with
        GCC 5 in armhf (LP: #1482274)
      . [enhancement] Mir lacks relative mouse support (LP: #1276322)
      . ShmBuffer ignores pixel_format (LP: #1424909)
      . Fullscreen bypassed clients stutter with double buffers when other
        clients are running (LP: #1447896)
      . [regression] Demo servers crash on start-up if MIR_ENABLE_TESTS=OFF
        (LP: #1439078)
      . [regression] The software curs...