packages: The 'source' can be any lowerable object.

* guix/packages.scm (expand-input): Use 'struct?' instead of 'origin?'
when matching SOURCE.
(package-source-derivation): Use 'lower-object' instead of
'origin->derivation'.
* tests/packages.scm ("package-source-derivation, local-file"): New
test.
* doc/guix.texi (package Reference): Update 'source' documentation
accordingly.

1 files changed, 6 insertions, 2 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index 0a30b52fca9..18a1960cf71 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -2503,8 +2503,12 @@ The name of the package, as a string.
 The version of the package, as a string.
 
 @item @code{source}
-An origin object telling how the source code for the package should be
-acquired (@pxref{origin Reference}).
+An object telling how the source code for the package should be
+acquired.  Most of the time, this is an @code{origin} object, which
+denotes a file fetched from the Internet (@pxref{origin Reference}).  It
+can also be any other ``file-like'' object such as a @code{local-file},
+which denotes a file from the local file system (@pxref{G-Expressions,
+@code{local-file}}).
 
 @item @code{build-system}
 The build system that should be used to build the package (@pxref{Build