This patch is from the upstream pull request
https://github.com/chadaustin/sajson/pull/54.
It fixes linking with GCC.

diff --git a/include/sajson.h b/include/sajson.h
index 8b4e05a..1bd045b 100644
--- a/include/sajson.h
+++ b/include/sajson.h
@@ -138,12 +138,17 @@ constexpr inline size_t make_element(tag t, size_t value) {
 // header. This trick courtesy of Rich Geldreich's Purple JSON parser.
 template <typename unused = void>
 struct globals_struct {
+    static const unsigned char parse_flags[256];
+};
+typedef globals_struct<> globals;
+
 // clang-format off
 
     // bit 0 (1) - set if: plain ASCII string character
     // bit 1 (2) - set if: whitespace
     // bit 4 (0x10) - set if: 0-9 e E .
-    constexpr static const uint8_t parse_flags[256] = {
+    template <typename unused>
+    const unsigned char globals_struct<unused>::parse_flags[256] = {
      // 0    1    2    3    4    5    6    7      8    9    A    B    C    D    E    F
         0,   0,   0,   0,   0,   0,   0,   0,     0,   2,   2,   0,   0,   2,   0,   0, // 0
         0,   0,   0,   0,   0,   0,   0,   0,     0,   0,   0,   0,   0,   0,   0,   0, // 1
@@ -162,15 +167,13 @@ struct globals_struct {
     };
 
 // clang-format on
-};
-typedef globals_struct<> globals;
 
-constexpr inline bool is_plain_string_character(char c) {
+inline bool is_plain_string_character(char c) {
     // return c >= 0x20 && c <= 0x7f && c != 0x22 && c != 0x5c;
     return (globals::parse_flags[static_cast<unsigned char>(c)] & 1) != 0;
 }
 
-constexpr inline bool is_whitespace(char c) {
+inline bool is_whitespace(char c) {
     // return c == '\r' || c == '\n' || c == '\t' || c == ' ';
     return (globals::parse_flags[static_cast<unsigned char>(c)] & 2) != 0;
 }
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<div class='path'>path: <a href='/guix/log/?id=2baad07da40259dd10b68892818f0c6564054902'>root</a>/<a href='/guix/log/gnu?id=2baad07da40259dd10b68892818f0c6564054902'>gnu</a>/<a href='/guix/log/gnu/bootloader.scm?id=2baad07da40259dd10b68892818f0c6564054902'>bootloader.scm</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/gnu/bootloader.scm?id=2baad07da40259dd10b68892818f0c6564054902&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-10-28 00:17:24 +0200'>2023-10-28</span></td><td><a href='/guix/commit/gnu/bootloader.scm?id=344e39c928bdb8e6b7e5ac79d94535921a414a05'>profiles: Hooks honor the #:system parameter of ‘profile-derivation’.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;https://issues.guix.gnu.org/65225&gt;.

* guix/profiles.scm (info-dir-file, package-cache-file)
(info-dir-file, ghc-package-cache-file, ca-certificate-bundle)
(emacs-subdirs, gdk-pixbuf-loaders-cache-file, glib-schemas)
(gtk-icon-themes, gtk-im-modules, linux-module-database)
(xdg-desktop-database, xdg-mime-database, fonts-dir-file)
(manual-database, manual-database/optional): Add optional #:system
parameter and pass it to ‘gexp-&gt;derivation’.
(profile-derivation): Pass HOOK a second parameter, SYSTEM.
* gnu/bootloader.scm (efi-bootloader-profile)[efi-bootloader-profile-hook]:
Add optional #:system parameter and pass it to ‘gexp-&gt;derivation’.
* guix/channels.scm (package-cache-file): Likewise.
* tests/profiles.scm ("profile-derivation, #:system, and hooks"): New
test.

Reported-by: Tobias Geerinckx-Rice &lt;me@tobias.gr&gt;
</span></span></td><td>Ludovic Courtès</td></tr>
8218].</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/file.scm (file): Update to 5.37.
* gnu/packages/patches/file-CVE-2019-18218.patch: New file.
* gnu/packages/patches/file-CVE-2018-10360.patch: Delete file.
* gnu/local.mk (dist_patch_DATA): Adjust accordingly.
</span></span></td><td>Leo Famulari</td></tr>
<tr><td><span title='2019-05-01 23:11:41 +0200'>2019-05-01</span></td><td><a href='/guix/commit/gnu/packages/file.scm?id=3b458d5462e6bbd852c2dc5c6670d5655abf53f5'>Merge branch 'master' into core-updates</a></td><td>Marius Bakke</td></tr>
<tr><td><span title='2019-03-30 15:19:32 +0100'>2019-03-30</span></td><td><a href='/guix/commit/gnu/packages/file.scm?id=528ea990c3a815cb4b0ded913ea22cdc778839bd'>gnu: Use 'this-package' as a native input instead of 'self-native-input?'.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/file.scm (file)[self-native-input?]: Remove.
[native-inputs]: New field.
* gnu/packages/guile.scm (guile-1.8)[self-native-input?]: Remove.
[native-inputs]: New field.
(guile-2.0)[self-native-input?]: Remove.
[native-inputs]: Add THIS-PACKAGE when (%current-target-system) is true.
* gnu/packages/ncurses.scm (ncurses)[self-native-input?]: Remove.
[native-inputs]: Add THIS-PACKAGE when (%current-target-system) is true.
* gnu/packages/python-xyz.scm (python-file)[self-native-input?]: Remove.
[native-inputs]: New field.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-02-07 22:10:16 +0100'>2019-02-07</span></td><td><a href='/guix/commit/gnu/packages/file.scm?id=cc43d807c08af02d31770a011881990d46428737'>gnu: file: Incorporate grafted changes.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/file.scm (file)[replacement]: Remove.
[source](patches): New field.
(file/fixed): Remove variable.
</span></span></td><td>Marius Bakke</td></tr>