From: Rafael Sadowski <rafael@sizeofvoid.org>
Subject: Re: [libcxx22] fallout
To: Theo Buehler <tb@theobuehler.org>
Cc: ports@openbsd.org
Date: Tue, 25 Aug 2026 21:52:22 +0200

On Fri Aug 21, 2026 at 02:15:34PM +0200, Theo Buehler wrote:
> Here is the directly libcxx22-related breakage of my first bulk.
> 
> There may be a few more because mono got stuck with a weird error.  And
> I did not try to build the V8 monsters: codex, deno, chromiums and a few
> others because my machine isn't beefy enough. I don't think anything
> super important is directly affected or hiding behind those. So as far
> as ports are concerned, I think we can land libcxx22 whenever we want:
> 
> audio/ncmpcpp
> audio/rubberband
> cad/freecad
> databases/mongodb/44
> games/cataclysm-dda
> games/dxx-rebirth
> games/flightgear/base
> games/keeperrl
> mail/kopano/core
> misc/subsurface
> shells/fish/v3
> textproc/lttoolbox
> 
> There are basically two main classes of failures: comparison operators
> and locale things and a few odd ones like fish/v3 and 
> 
> audio/ncmpcpp
> /usr/include/c++/v1/__algorithm/sift_down.h:49:39: error: no matching function for call to object of type 'LocaleBasedSorting'
>    49 |   } else if ((__child + 1) < __len && __comp(__first[__child], __first[__child + 1])) {
>       |                                       ^~~~~~
> 

The lambdas are more or less a workaround from me.

I think, the much cleaner fix would be to teach LocaleBasedSorting to
handle all this, but that means digging even depper into the Boost
lib. I don't want go this way. Anyone?

diff --git a/audio/ncmpcpp/patches/patch-src_screens_sel_items_adder_cpp b/audio/ncmpcpp/patches/patch-src_screens_sel_items_adder_cpp
new file mode 100644
index 00000000000..8f4ca627847
--- /dev/null
+++ b/audio/ncmpcpp/patches/patch-src_screens_sel_items_adder_cpp
@@ -0,0 +1,16 @@
+Fix build with libc++22: Boost operator[] proxy breaks template argument
+deduction in LocaleBasedSorting.
+Index: src/screens/sel_items_adder.cpp
+--- src/screens/sel_items_adder.cpp.orig
++++ src/screens/sel_items_adder.cpp
+@@ -254,7 +254,9 @@ void SelectedItemsAdder::populatePlaylistSelector(Base
+ 			));
+ 		};
+ 		std::sort(m_playlist_selector.beginV()+begin, m_playlist_selector.endV(),
+-			LocaleBasedSorting(std::locale(), Config.ignore_leading_the));
++			[cmp = LocaleBasedSorting(std::locale(), Config.ignore_leading_the)]
++			(const Entry &a, const Entry &b) { return cmp(a, b); });
++
+ 		if (begin < m_playlist_selector.size())
+ 			m_playlist_selector.addSeparator();
+ 	}
diff --git a/audio/ncmpcpp/patches/patch-src_screens_tag_editor_cpp b/audio/ncmpcpp/patches/patch-src_screens_tag_editor_cpp
new file mode 100644
index 00000000000..24a6fa9d851
--- /dev/null
+++ b/audio/ncmpcpp/patches/patch-src_screens_tag_editor_cpp
@@ -0,0 +1,16 @@
+Fix build with libc++22: Boost operator[] proxy breaks template argument
+deduction in LocaleBasedSorting.
+Index: src/screens/tag_editor.cpp
+--- src/screens/tag_editor.cpp.orig
++++ src/screens/tag_editor.cpp
+@@ -289,7 +289,9 @@ void TagEditor::update()
+ 				Dirs->highlight(Dirs->size()-1);
+ 		};
+ 		std::sort(Dirs->beginV()+1, Dirs->endV(),
+-			LocaleBasedSorting(std::locale(), Config.ignore_leading_the));
++			[cmp = LocaleBasedSorting(std::locale(), Config.ignore_leading_the)]
++			(const std::pair<std::string, std::string> &a,
++			 const std::pair<std::string, std::string> &b) { return cmp(a, b); });
+ 		Dirs->display();
+ 	}
+