From d128cca4fff9c4e717f1d45218660f02f04d3b66 Mon Sep 17 00:00:00 2001
From: Hugo Buddelmeijer <hugo@buddelmeijer.nl>
Date: Wed, 17 Dec 2025 10:42:08 +0100
Subject: [PATCH] gnu: python-abjad: Fix build.

* gnu/packages/music.scm (python-abjad): Fix build.
[arguments]<#:phases>: Add 'fix-docstring phase.

Change-Id: Ic1d36183d47d6a2d65a2f3be25596802eb48ea03
Signed-off-by: Sharlatan Hellseher <sharlatanus@gmail.com>
---
 gnu/packages/music.scm | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/gnu/packages/music.scm b/gnu/packages/music.scm
index a14ae098bca608b493789557a5b4ca02657b4a7d..3cb8e6f9c29475f14d5ba655207332bb3963f825 100644
--- a/gnu/packages/music.scm
+++ b/gnu/packages/music.scm
@@ -3172,6 +3172,7 @@ using a system-independent interface.")
 (define-public python-abjad
   (package
     (name "python-abjad")
+    ;; 3.19 is the last version that supports Python 3.11; newer require 3.12.
     (version "3.19")
     (source
      (origin
@@ -3183,6 +3184,16 @@ using a system-independent interface.")
        (sha256
         (base32 "1cgcnmwzxx2hr21pqm1hbsknpad748yw3gf7jncsb3w1azhjypzm"))))
     (build-system pyproject-build-system)
+    (arguments
+     (list
+      #:phases
+      #~(modify-phases %standard-phases
+          ;; Error message changed in latest python-roman; fixed in abjad 3.21.
+          (add-after 'unpack 'fix-docstring
+            (lambda _
+              (substitute* "abjad/string.py"
+                (("roman.InvalidRomanNumeralError: Invalid Roman numeral: Allegro")
+                 "roman.InvalidRomanNumeralError...")))))))
     (inputs
      (list lilypond))
     (native-inputs