[tracker] configure: Make libseccomp only mandatory on linux

[Carlos Garnacho <carlosg src gnome org>]

commit bdf25c78ee11e25bf017e37c78f7c07a2f7ac29a
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu Dec 22 14:26:09 2016 +0100

    configure: Make libseccomp only mandatory on linux
    
    If other unices want a similar level of protection, additional
    implementations should be added. In the mean time, it's just
    harsh to make tracker impossible to compile there.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=764786

 configure.ac |   11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 3c13d8d..0c09eb9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -186,6 +186,12 @@ if test "x$have_function" = "xno" ; then
             [Defined for compilers not supporting __FUNCTION__])
 fi
 
+case $host in
+    *-*-linux*)
+        tracker_os_linux=yes
+        ;;
+esac
+
 # Remember CFLAGS upon entering configure...
 CFLAGS="$CFLAGS"
 
@@ -2614,8 +2620,9 @@ if test "$have_libseccomp" = "yes"; then
    LIBTRACKER_COMMON_LIBS="$LIBTRACKER_COMMON_LIBS $LIBSECCOMP_LIBS"
    LIBTRACKER_COMMON_CFLAGS="$LIBTRACKER_COMMON_CFLAGS $LIBSECCOMP_CFLAGS"
    AC_DEFINE(HAVE_LIBSECCOMP, [], [Define if we have libseccomp])
-else
-  AC_MSG_ERROR([Libseccomp is mandatory for sandboxed metadata extraction])
+# seccomp is a linux thing
+elif test "$tracker_os_linux" = "yes"; then
+   AC_MSG_ERROR([Libseccomp is mandatory for sandboxed metadata extraction])
 fi
 
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