From: Nam Nguyen <namn@messagemode2.com>
Subject: Re: [libcxx22] fallout
To: Rafael Sadowski <rafael@sizeofvoid.org>
Cc: ports@openbsd.org
Date: Fri, 28 Aug 2026 00:40:55 -0700

Rafael Sadowski writes:

> 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?

I tested adding items to playlist and opening the tag editor and it hit
both codepaths. Types match up.

browser.cpp uses stable_sort so it is different. It is a bit strange
that PlaylistEditor::update() has the old style and it works fine:
std::sort(Playlists.beginV(), Playlists.endV(),
LocaleBasedSorting(std::locale(), Config.ignore_leading_the));
Playlists = NC::Menu<MPD::Playlist>
bool operator()(const MPD::Playlist &a, const MPD::Playlist &b) const {

ok namn@

>
> 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();
> + 	}
> +