Do not assume the SDL_image and SLD_mixer libraries are installed at the same
prefix reported by sdl-config, but instead get flags from the pkg-config files
installed with these libraries.

--- a/SConscript	2011-12-24 15:46:47.000000000 -0600
+++ b/SConscript	2014-06-12 21:20:45.702668330 -0500
@@ -199,7 +199,13 @@
                 self.fatal_error += "  * library 'png' not found\n"
 
     def configure_sdl(self):
-        if self.conf.CheckMyProgram('sdl-config'):
+        if self.conf.CheckMyProgram('pkg-config'):
+            self.conf.env.ParseConfig("pkg-config --cflags --libs sdl")
+            for sdllib in ['image', 'mixer']:
+                self.conf.env.ParseConfig("pkg-config --cflags --libs SDL_%s" % sdllib)
+                if not self.conf.CheckSDLLib(sdllib):
+                    self.fatal_error += "  * SDL library '%s' not found\n" % sdllib
+        elif self.conf.CheckMyProgram('sdl-config'):
             self.conf.env.ParseConfig("sdl-config  --cflags --libs | sed 's/-I/-isystem/g'")
             for sdllib in ['image', 'mixer']:
                 if not self.conf.CheckSDLLib(sdllib):
8f7716ad65d670eb7654a03a0e785d'>refs</a><a class='active' href='/guix/log/gnu/installer/proxy.scm'>log</a><a href='/guix/tree/gnu/installer/proxy.scm?id=318581c5fc8f7716ad65d670eb7654a03a0e785d'>tree</a><a href='/guix/commit/gnu/installer/proxy.scm?id=318581c5fc8f7716ad65d670eb7654a03a0e785d'>commit</a><a href='/guix/diff/gnu/installer/proxy.scm?id=318581c5fc8f7716ad65d670eb7654a03a0e785d'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/installer/proxy.scm'>
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<div class='path'>path: <a href='/guix/log/?id=318581c5fc8f7716ad65d670eb7654a03a0e785d'>root</a>/<a href='/guix/log/gnu?id=318581c5fc8f7716ad65d670eb7654a03a0e785d'>gnu</a>/<a href='/guix/log/gnu/installer?id=318581c5fc8f7716ad65d670eb7654a03a0e785d'>installer</a>/<a href='/guix/log/gnu/installer/proxy.scm?id=318581c5fc8f7716ad65d670eb7654a03a0e785d'>proxy.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/installer/proxy.scm?id=318581c5fc8f7716ad65d670eb7654a03a0e785d&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-12-11 21:37:07 +0100'>2020-12-11</span></td><td><a href='/guix/commit/gnu/installer/proxy.scm?id=8361817bf693742757b096468198626f297bb09e'>install: Discover local substitute servers.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/installer/substitutes.scm: New file.
* gnu/installer/newt/substitutes.scm: New file.
* gnu/local.mk (INSTALLER_MODULES): Add them.
* po/guix/POTFILES.in: Add gnu/installer/newt/substitutes.scm.
* gnu/installer/proxy.scm (with-silent-shepherd): Move to ...
* gnu/installer/utils.scm: ... here.
* gnu/installer/record.scm (&lt;installer&gt;)[substitutes-page]: New field.
* gnu/installer/newt.scm (substitutes-page): New procedure,
(newt-installer): register it.
* gnu/installer.scm (installer-steps): Add "substitutes-page" step.
* gnu/system/install.scm (%installation-services): Add avahi-service-type and
enable substitute server discover in guix-service-type.
[&lt;name-service-switch&gt;]: Set it to %mdns-host-lookup-nss.
</span></span></td><td>Mathieu Othacehe</td></tr>