Support overriding architecture

In the same way as os, hostname and user.

test/test_unit_set_local_alt_values.py

@@ -7,28 +7,31 @@
     'override', [
         False,
         'class',
+        'arch',
         'os',
         'hostname',
         'user',
         ],
     ids=[
         'no-override',
         'override-class',
+        'override-arch',
         'override-os',
         'override-hostname',
         'override-user',
         ]
     )
 @pytest.mark.usefixtures('ds1_copy')
 def test_set_local_alt_values(
-        runner, yadm, paths, tst_sys, tst_host, tst_user, override):
+        runner, yadm, paths, tst_arch, tst_sys, tst_host, tst_user, override):
     """Use issue_legacy_path_warning"""
     script = f"""
         YADM_TEST=1 source {yadm} &&
         set_operating_system &&
         YADM_DIR={paths.yadm} YADM_DATA={paths.data} configure_paths &&
         set_local_alt_values
         echo "class='$local_class'"
+        echo "arch='$local_arch'"
         echo "os='$local_system'"
         echo "host='$local_host'"
         echo "user='$local_user'"
@@ -46,6 +49,11 @@ def test_set_local_alt_values(
     else:
         assert "class=''" in run.out
 
+    if override == 'arch':
+        assert "arch='override'" in run.out
+    else:
+        assert f"arch='{tst_arch}'" in run.out
+
     if override == 'os':
         assert "os='override'" in run.out
     else:

yadm

@@ -837,7 +837,7 @@ EOF
 function config() {
 
   use_repo_config=0
-  local_options="^local\.(class|os|hostname|user)$"
+  local_options="^local\.(class|arch|os|hostname|user)$"
   for option in "$@"; do
     [[ "$option" =~ $local_options ]] && use_repo_config=1
   done

yadm.1

@@ -427,7 +427,7 @@ Disable the permission changes to
 This feature is enabled by default.
 
 .RE
-The following four "local" configurations are not stored in the
+The following five "local" configurations are not stored in the
 .IR $HOME/.config/yadm/config,
 they are stored in the local repository.
 
@@ -436,6 +436,9 @@ they are stored in the local repository.
 Specify a class for the purpose of symlinking alternate files.
 By default, no class will be matched.
 .TP
+.B local.arch
+Override the architecture for the purpose of symlinking alternate files.
+.TP
 .B local.hostname
 Override the hostname for the purpose of symlinking alternate files.
 .TP
@@ -601,8 +604,9 @@ command. The following sets the class to be "Work".
 
   yadm config local.class Work
 
-Similarly, the values of os, hostname, and user can be manually overridden
-using the configuration options
+Similarly, the values of architecture, os, hostname, and user can be manually
+overridden using the configuration options
+.BR local.arch ,
 .BR local.os ,
 .BR local.hostname ,
 and