[bug#41521] [PATCH] build: substitute*: Fix typo in example.

[Efraim Flashner]

* guix/build/utils.scm (substitute*): Fix typo in example in docstring,
use consistent variable names.
---

The variable is 'letters' on the line above, so it should be 'letters'
on the replacement line too.

---
 guix/build/utils.scm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/guix/build/utils.scm b/guix/build/utils.scm
index 419c10195b..bcae0f758a 100644
--- a/guix/build/utils.scm
+++ b/guix/build/utils.scm
@@ -800,7 +800,7 @@ sub-expression.  For example:
      ((\"hello\")
       \"good morning\\n\")
      ((\"foo([a-z]+)bar(.*)$\" all letters end)
-      (string-append \"baz\" letter end)))
+      (string-append \"baz\" letters end)))
 
 Here, anytime a line of FILE contains \"hello\", it is replaced by \"good
 morning\".  Anytime a line of FILE matches the second regexp, ALL is bound to
-- 
2.26.2