git: ef23f41eb5 - main - porter-handbook: Document recently added CABAL_REVISION knob.

The branch main has been updated by arrowd (ports committer):

URL: https://cgit.FreeBSD.org/doc/commit/?id=ef23f41eb565c84fc675bc9dbf1810e51c616799

commit ef23f41eb565c84fc675bc9dbf1810e51c616799
Author:     Gleb Popov <[email protected]>
AuthorDate: 2022-11-23 08:43:07 +0000
Commit:     Gleb Popov <[email protected]>
CommitDate: 2022-11-23 11:48:05 +0000

    porter-handbook: Document recently added CABAL_REVISION knob.
    
    Reviewed By: #docs, fernape
    
    Differential Revision: https://reviews.freebsd.org/D37474
---
 documentation/content/en/books/porters-handbook/uses/_index.adoc | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/documentation/content/en/books/porters-handbook/uses/_index.adoc b/documentation/content/en/books/porters-handbook/uses/_index.adoc
index 3a05b70c57..dad36f57b2 100644
--- a/documentation/content/en/books/porters-handbook/uses/_index.adoc
+++ b/documentation/content/en/books/porters-handbook/uses/_index.adoc
@@ -199,10 +199,14 @@ This argument is implicitly added if `USE_GITHUB` or `USE_GITLAB` is present.
 
 The framework provides the following variables:
 
+`CABAL_REVISION`::
+Haskell packages hosted on Hackage may have revisions.
+Set this knob to an integer number to pull in revised package description.
+
 `USE_CABAL`::
 If the software uses Haskell dependencies, list them in this variable.
 Each item should be present on Hackage and be listed in form `packagename-_0.1.2_`.
-Dependencies can have revisions, which are specified after the `_` symbol.
+Dependencies can have revisions too, which are specified after the `_` symbol.
 Automatic generation of the dependency list is supported, see crossref:special[using-cabal,Building Haskell Applications with `cabal`].
 
 `CABAL_FLAGS`::