livemedia-creator: log more failure information

This switches on the rc checking in execWithRedirect and logs the error
it raises.

src/sbin/livemedia-creator

@@ -366,9 +366,11 @@ class VirtualInstall(object):
             args.append("--arch")
             args.append(arch)
 
-        rc = execWithRedirect("virt-install", args)
-        if rc:
-            raise InstallError("Problem starting virtual install")
+        log.info("Running virt-install.")
+        try:
+            execWithRedirect("virt-install", args, raise_err=True)
+        except subprocess.CalledProcessError as e:
+            raise InstallError("Problem starting virtual install: %s" % e)
 
         conn = libvirt.openReadOnly(None)
         dom = conn.lookupByName(self.virt_name)
@@ -646,8 +648,13 @@ def novirt_install(opts, disk_img, disk_size, repo_url):
     # Make sure anaconda has the right product and release
     os.environ["ANACONDA_PRODUCTNAME"] = opts.project
     os.environ["ANACONDA_PRODUCTVERSION"] = opts.releasever
-    rc = execWithRedirect("anaconda", args)
-
+    log.info("Running anaconda.")
+    try:
+        execWithRedirect("anaconda", args, raise_err=True)
+    except subprocess.CalledProcessError as e:
+        log.error("Running anaconda failed: %s", e)
+        raise InstallError("novirt_install failed")
+    finally:
         # Move the anaconda logs over to a log directory
         log_dir = os.path.abspath(os.path.dirname(opts.logfile))
         log_anaconda = joinpaths(log_dir, "anaconda")
@@ -673,9 +680,6 @@ def novirt_install(opts, disk_img, disk_size, repo_url):
         if selinux_enforcing:
             selinux.security_setenforce(1)
 
-    if rc:
-        raise InstallError("novirt_install failed")
-
     if opts.qcow2:
         log.info("Converting %s to qcow2", disk_img)
         qcow2_args = []
@@ -697,7 +701,7 @@ def novirt_install(opts, disk_img, disk_size, repo_url):
         shutil.rmtree(ROOT_PATH)
 
         if rc:
-            raise InstallError("novirt_install failed")
+            raise InstallError("novirt_install mktar failed: rc=%s" % rc)
 
 
 def virt_install(opts, install_log, disk_img, disk_size):