Mupen64Plus supports a single data directory and a single plugin directory in
its configuration, yet we need data and plugin files from a variety of
packages.  The best way to deal with this is to install all packages from
which data and plugin files are needed into one's profile, and point the
configuration there.  Hence, the ui-console package provides propagated inputs
for packages with the most important data and plugin files, and this patch
provides the user instructions on what needs to be done in order to have
Mupen64Plus find the relevant data and plugins.

--- a/src/plugin.c
+++ b/src/plugin.c
@@ -122,6 +122,22 @@ m64p_error PluginSearchLoad(m64p_handle ConfigUI)
     {
         const char *plugindir = (*ConfigGetParamString)(ConfigUI, "PluginDir");
         lib_filelist = osal_library_search(plugindir);
+        /* Guix specific */
+        if (lib_filelist == NULL)
+        {
+            DebugMessage(M64MSG_ERROR, "No plugins found in PluginDir path: %s", plugindir);
+            DebugMessage(M64MSG_ERROR,
+                         "\n\n"
+                         "*********************************\n"
+                         "*** Notice for GNU Guix users ***\n"
+                         "*********************************\n"
+                         "\n"
+                         "You might want to edit your mupen64plus.cfg (in $XDG_CONFIG_HOME by default)\n"
+                         "and set SharedDataPath to /path/to/my_guix_profile/share/mupen64plus and\n"
+                         "PluginDir to /path/to/my_guix_profile/lib/mupen64plus so that data and plugins\n"
+                         "are found.\n"
+                         "\n");
+        }
     }
 
     /* if still no plugins found, search some common system folders */
on value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=c0773455397746b10194bc14c7cef144f4095b65'>root</a>/<a href='/guix/log/gnu?id=c0773455397746b10194bc14c7cef144f4095b65'>gnu</a>/<a href='/guix/log/gnu/build?id=c0773455397746b10194bc14c7cef144f4095b65'>build</a>/<a href='/guix/log/gnu/build/chromium-extension.scm?id=c0773455397746b10194bc14c7cef144f4095b65'>chromium-extension.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/build/chromium-extension.scm?id=c0773455397746b10194bc14c7cef144f4095b65&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-07-20 16:50:08 +0200'>2022-07-20</span></td><td><a href='/guix/commit/gnu/build/chromium-extension.scm?id=cda3de3b7de46346457e75eb7022bc76a34c2d4f'>gnu: modifying make-chromium-extension to rely on node-crx3.</a><span class='msg-avail'>...</span></td><td>Nicolas Graves</td></tr>
<tr><td><span title='2021-12-23 03:07:34 +0100'>2021-12-23</span></td><td><a href='/guix/commit/gnu/build/chromium-extension.scm?id=a89d65eec1948cbcbf9936939906fae9cdabf1e7'>chromium-extension: Avoid another usage of the store-mapped /tmp.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2021-12-16 22:21:13 +0100'>2021-12-16</span></td><td><a href='/guix/commit/gnu/build/chromium-extension.scm?id=aec6bd0169bb855a3ec70f5edec0701d0a66ce9d'>chromium-extension: Build .crx files in a deterministic fashion.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2021-12-16 22:21:13 +0100'>2021-12-16</span></td><td><a href='/guix/commit/gnu/build/chromium-extension.scm?id=40ebf85b865cb942c2551bfdc2ca3065eb3d9186'>chromium-extension: Avoid usage of gcrypt at evaluation time.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2021-12-16 22:21:13 +0100'>2021-12-16</span></td><td><a href='/guix/commit/gnu/build/chromium-extension.scm?id=173860eb41102c5af2cfdc0404808075d5a5ff3a'>chromium-extension: Reduce imported-modules scope.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2021-12-16 22:21:13 +0100'>2021-12-16</span></td><td><a href='/guix/commit/gnu/build/chromium-extension.scm?id=f59bb27557ee8d115efb120292112387a6d23490'>chromium-extension: Simplify builder code.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>