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;
 }
 name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=15f086232353fe5f1b9b5dd44cccd770a55fefbd'>root</a>/<a href='/guix/log/gnu?id=15f086232353fe5f1b9b5dd44cccd770a55fefbd'>gnu</a>/<a href='/guix/log/gnu/build?id=15f086232353fe5f1b9b5dd44cccd770a55fefbd'>build</a>/<a href='/guix/log/gnu/build/secret-service.scm?id=15f086232353fe5f1b9b5dd44cccd770a55fefbd'>secret-service.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/build/secret-service.scm?id=15f086232353fe5f1b9b5dd44cccd770a55fefbd&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2024-02-10 22:59:43 +0100'>2024-02-10</span></td><td><a href='/guix/commit/gnu/build/secret-service.scm?id=f331a667d3827c5c7603c87956c601d5e42ef82b'>services: secret-service: Make the endpoint configurable.</a><span class='msg-avail'>...<span class='msg-tooltip'>Until now, the secret service had a hard-coded TCP endpoint on port
1004.  This change lets users specify arbitrary socket addresses.

* gnu/build/secret-service.scm (socket-address-&gt;string): New procedure,
taken from Shepherd.
(secret-service-send-secrets): Replace ‘port’ by ‘address’ and adjust
accordingly.
(secret-service-receive-secrets): Likewise.
* gnu/services/virtualization.scm (secret-service-shepherd-services):
Likewise.
(secret-service-operating-system): Add optional ‘address’ parameter and
honor it.  Adjust ‘start’ method accordingly.

Change-Id: I87a9514f1c170dca756ce76083d7182c6ebf6578
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2023-10-01 22:58:19 +0200'>2023-10-01</span></td><td><a href='/guix/commit/gnu/build/secret-service.scm?id=e90a972ce232a6a57995df1ed90c9ddbaf5dbcae'>secret-service: Increase default handshake timeout.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/build/secret-service.scm (secret-service-send-secrets):
Increase #:handshake-timeout.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2023-05-06 17:12:45 +0200'>2023-05-06</span></td><td><a href='/guix/commit/gnu/build/secret-service.scm?id=e88bf64e6fa61265dca81a799ce824f639a2875a'>services: dbus-service, secret-service: Do not cause (fibers) to be loaded.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/build/dbus-service.scm (sleep*): Pass #:ensure #f to 'resolve-module'.
* gnu/build/secret-service.scm (wait-for-readable-fd): Likewise.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-09-13 00:31:04 +0200'>2022-09-13</span></td><td><a href='/guix/commit/gnu/build/secret-service.scm?id=491dd62b38e1772f3e50de58118d9b9ac97272ff'>secret-service: Mark sockets as SOCK_CLOEXEC.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/build/secret-service.scm (secret-service-send-secrets)
(secret-service-receive-secrets): Pass SOCK_CLOEXEC to 'socket'.
</span></span></td><td>Ludovic Courtès</td></tr>