Upstream status: Adapted from upstream.

From d3d968e5835f449d7ea715f45160db81ea906303 Mon Sep 17 00:00:00 2001
From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date: Tue, 16 Aug 2022 20:29:54 +0200
Subject: [PATCH] Fix build on GNU/Hurd

There is no path length limitation there, even via pathconf.  But glibc
provides a getcwd function that allocates the buffer dynamically so we can
just leverage that.
---
 include/ghc/filesystem.hpp | 7 +++++++
 1 file changed, 7 insertions(+)

--- a/filesystem/filesystem.hpp.orig	2022-08-11 22:14:32.000000000 +0200
+++ b/filesystem/filesystem.hpp	2023-06-13 07:26:25.310000000 +0200
@@ -4081,6 +4081,13 @@
         return path();
     }
     return path(std::wstring(buffer.get()), path::native_format);
+#elif defined(__GLIBC__)
+    std::unique_ptr<char, decltype(&std::free)> buffer { ::getcwd(NULL, 0), std::free };
+    if (buffer == nullptr) {
+        ec = detail::make_system_error();
+        return path();
+    }
+    return path(buffer.get());
 #else
     size_t pathlen = static_cast<size_t>(std::max(int(::pathconf(".", _PC_PATH_MAX)), int(PATH_MAX)));
     std::unique_ptr<char[]> buffer(new char[pathlen + 1]);
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<div class='path'>path: <a href='/guix/log/?id=f6e06e8b15d1fa6c17d8fd21f95b26985b4e1674'>root</a>/<a href='/guix/log/tests?id=f6e06e8b15d1fa6c17d8fd21f95b26985b4e1674'>tests</a>/<a href='/guix/log/tests/guix-daemon.sh?id=f6e06e8b15d1fa6c17d8fd21f95b26985b4e1674'>guix-daemon.sh</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/tests/guix-daemon.sh?id=f6e06e8b15d1fa6c17d8fd21f95b26985b4e1674&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-09-28 21:06:36 -0500'>2020-09-28</span></td><td><a href='/guix/commit/tests/guix-daemon.sh?id=d8934360d2453a403b5433e71d09188e4ed23b57'>tests: Simplify shell exit status negation;</a><span class='msg-avail'>...</span></td><td>Eric Bavier</td></tr>
<tr><td><span title='2019-10-16 22:53:40 +0200'>2019-10-16</span></td><td><a href='/guix/commit/tests/guix-daemon.sh?id=81c580c8664bfeeb767e2c47ea343004e88223c7'>daemon: Make 'profiles/per-user' non-world-writable.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-06-27 23:33:48 +0200'>2019-06-27</span></td><td><a href='/guix/commit/tests/guix-daemon.sh?id=5cc1075a76392666d3d733837f5c6252b1e48002'>Merge branch 'master' into core-updates</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-06-27 11:14:42 +0200'>2019-06-27</span></td><td><a href='/guix/commit/tests/guix-daemon.sh?id=c30d117822a8ca26cd8c06c0a3974955bef68eac'>tests: Avoid TCP port collision between lint.scm and guix-daemon.sh.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-06-14 21:57:39 +0200'>2019-06-14</span></td><td><a href='/guix/commit/tests/guix-daemon.sh?id=1ba0b1e6ec41afd94a3c5f907b1122204dcb5d9d'>packages: Remove 'search-bootstrap-binary'.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-02-04 00:03:30 +0100'>2019-02-04</span></td><td><a href='/guix/commit/tests/guix-daemon.sh?id=a87d66f371da2a84d7bba1cae58b71c9c9af73aa'>daemon: Rename 'NIX_STATE_DIR' and 'NIX_DB_DIR' environment variables.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-01-21 23:09:55 +0100'>2019-01-21</span></td><td><a href='/guix/commit/tests/guix-daemon.sh?id=f9e8a12379c6fefc9e5c3c7fc3926599bbefc013'>store: Rename '&amp;nix-error' to '&amp;store-error'.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>