commit 0f2c819
Author: Matthias Klumpp <matthias@tenstral.net>
Date:   Tue Apr 11 14:50:46 2023 +0200

    Make building the RPMMD backend optional
    
    CC: #109

diff --git a/meson_options.txt b/meson_options.txt
index c044b2e..3d18255 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -2,8 +2,13 @@
 # Options for AppStream Generator
 #
 
+option('rpmmd',
+       type: 'boolean',
+       value: true,
+       description: 'Build the RPM-MD backend..'
+)
 option('download-js',
        type: 'boolean',
        value: true,
-       description: 'Whether we should download JavaScript with Yarn automatically.'
+       description: 'Download JavaScript with Yarn automatically.'
 )
diff --git a/src/asgen/defines.d.in b/src/asgen/defines.d.in
index af49792..1d8c91b 100644
--- a/src/asgen/defines.d.in
+++ b/src/asgen/defines.d.in
@@ -25,3 +25,6 @@ public enum DATADIR = "@datadir@";
 
 // current version of the tool
 public enum ASGEN_VERSION = "@asgen_version@";
+
+// whether the RPM-MD backend is enabled
+public enum HAVE_RPMMD = @build_rpmmd@;
diff --git a/src/asgen/engine.d b/src/asgen/engine.d
index 2b4e18c..8ecd9ba 100644
--- a/src/asgen/engine.d
+++ b/src/asgen/engine.d
@@ -41,14 +41,16 @@ import asgen.reportgenerator;
 import asgen.localeunit : LocaleUnit;
 import asgen.cptmodifiers : InjectedModifications;
 import asgen.utils : copyDir, stringArrayToByteArray, getCidFromGlobalID;
+import asgen.defines : HAVE_RPMMD;
 
 import asgen.backends.interfaces;
 import asgen.backends.dummy;
 import asgen.backends.debian;
 import asgen.backends.ubuntu;
 import asgen.backends.archlinux;
-import asgen.backends.rpmmd;
 import asgen.backends.alpinelinux;
+static if (HAVE_RPMMD) import asgen.backends.rpmmd;
+
 
 import asgen.iconhandler : IconHandler;
 
@@ -89,8 +91,12 @@ public:
                 pkgIndex = new ArchPackageIndex (conf.archiveRoot);
                 break;
             case Backend.RpmMd:
-                pkgIndex = new RPMPackageIndex (conf.archiveRoot);
-                break;
+                static if (HAVE_RPMMD) {
+                    pkgIndex = new RPMPackageIndex (conf.archiveRoot);
+                    break;
+                } else {
+                    throw new Exception ("This appstream-generator was built without support for RPM-MD!");
+                }
             case Backend.Alpinelinux:
                 pkgIndex = new AlpinePackageIndex (conf.archiveRoot);
                 break;
diff --git a/src/asgen/meson.build b/src/asgen/meson.build
index be49dba..5252f14 100644
--- a/src/asgen/meson.build
+++ b/src/asgen/meson.build
@@ -2,6 +2,7 @@
 conf_data = configuration_data()
 conf_data.set('datadir', join_paths(get_option('prefix'), get_option('datadir'), 'appstream'))
 conf_data.set('asgen_version', asgen_version)
+conf_data.set('build_rpmmd', get_option('rpmmd')? 'true' : 'false')
 configure_file(input : 'defines.d.in',
                output: 'defines.d',
                configuration: conf_data
@@ -63,12 +64,16 @@ backend_sources = [
     'backends/ubuntu/package.d',
     'backends/ubuntu/ubupkg.d',
     'backends/ubuntu/ubupkgindex.d',
-
-    'backends/rpmmd/package.d',
-    'backends/rpmmd/rpmpkg.d',
-    'backends/rpmmd/rpmpkgindex.d',
 ]
 
+if get_option('rpmmd')
+    backend_sources += [
+        'backends/rpmmd/package.d',
+        'backends/rpmmd/rpmpkg.d',
+        'backends/rpmmd/rpmpkgindex.d',
+    ]
+endif
+
 #
 # Build and test
 #