Modules: Improve error reporting

- Remaining modules [networkcfg] [openrcdmcryptcfg] [rawfs] with
   code that throws on bad configuration. Replace with meaningful
   error messages, to better check cases of SyntaxError &c.

src/modules/networkcfg/main.py

@@ -41,8 +41,13 @@ def run():
     """
     Setup network configuration
     """
-
     root_mount_point = libcalamares.globalstorage.value("rootMountPoint")
+
+    if root_mount_point is None:
+        libcalamares.utils.warning("rootMountPoint is empty, {!s}".format(root_mount_point))
+        return (_("Configuration Error"),
+                _("No root mount point is given for <pre>{!s}</pre> to use." ).format("networkcfg"))
+
     source_nm = "/etc/NetworkManager/system-connections/"
     target_nm = os.path.join(
         root_mount_point, "etc/NetworkManager/system-connections/"

src/modules/openrcdmcryptcfg/main.py

@@ -73,6 +73,15 @@ def run():
     dmcrypt_conf_path = libcalamares.job.configuration["configFilePath"]
     partitions = libcalamares.globalstorage.value("partitions")
 
+    if not partitions:
+        libcalamares.utils.warning("partitions is empty, {!s}".format(partitions))
+        return (_("Configuration Error"),
+                _("No partitions are defined for <pre>{!s}</pre> to use." ).format("openrcdmcryptcfg"))
+    if not root_mount_point:
+        libcalamares.utils.warning("rootMountPoint is empty, {!s}".format(root_mount_point))
+        return (_("Configuration Error"),
+                _("No root mount point is given for <pre>{!s}</pre> to use." ).format("openrcdmcryptcfg"))
+
     dmcrypt_conf_path = dmcrypt_conf_path.lstrip('/')
 
     return write_dmcrypt_conf(partitions, root_mount_point, dmcrypt_conf_path)

src/modules/rawfs/main.py

@@ -166,6 +166,11 @@ def run():
     filesystems = list()
     partitions = libcalamares.globalstorage.value("partitions")
 
+    if not partitions:
+        libcalamares.utils.warning("partitions is empty, {!s}".format(partitions))
+        return (_("Configuration Error"),
+                _("No partitions are defined for <pre>{!s}</pre> to use." ).format("rawfs"))
+
     for partition in partitions:
         if partition["mountPoint"]:
             for src in libcalamares.job.configuration["targets"]: