spack external find: add search path customization (#30479)

lib/spack/spack/cmd/external.py

@@ -37,6 +37,9 @@ def setup_parser(subparser):
     find_parser.add_argument(
         '--not-buildable', action='store_true', default=False,
         help="packages with detected externals won't be built with Spack")
+    find_parser.add_argument(
+        '-p', '--path', default=None, action='append',
+        help="Alternative search paths for finding externals. May be repeated")
     find_parser.add_argument(
         '--scope', choices=scopes, metavar=scopes_metavar,
         default=spack.config.default_modify_scope('packages'),
@@ -124,8 +127,10 @@ def external_find(args):
     if not args.tags and not packages_to_check:
         packages_to_check = spack.repo.path.all_packages()
 
-    detected_packages = spack.detection.by_executable(packages_to_check)
-    detected_packages.update(spack.detection.by_library(packages_to_check))
+    detected_packages = spack.detection.by_executable(
+        packages_to_check, path_hints=args.path)
+    detected_packages.update(spack.detection.by_library(
+        packages_to_check, path_hints=args.path))
 
     new_entries = spack.detection.update_configuration(
         detected_packages, scope=args.scope, buildable=not args.not_buildable

share/spack/spack-completion.bash

@@ -1024,7 +1024,7 @@ _spack_external() {
 _spack_external_find() {
     if $list_options
     then
-        SPACK_COMPREPLY="-h --help --not-buildable --scope --all -t --tag"
+        SPACK_COMPREPLY="-h --help --not-buildable -p --path --scope --all -t --tag"
     else
         _all_packages
     fi