doc: document automatically updating the pkgver variable

Signed-off-by: Allan McRae <allan@archlinux.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/doc/PKGBUILD.5.txt b/doc/PKGBUILD.5.txt
index a8d3f891..48820e5c 100644
--- a/doc/PKGBUILD.5.txt
+++ b/doc/PKGBUILD.5.txt
@@ -47,6 +47,11 @@ similar to `$_basekernver`.
 *pkgver*::
 	The version of the software as released from the author (e.g., '2.7.1').
 	The variable is not allowed to contain colons or hyphens.
++
+The `pkgver` variable can be automatically updated by providing a `pkgver()` function
+in the PKGBUILD that outputs the new package version.  This is run after downloading
+and extracting the sources so can use those files in determining the new `pkgver`.
+This is most useful when used with sources from version control systems (see below).
 
 *pkgrel*::
 	This is the release number specific to the Arch Linux release. This