Adapted from Debian: https://sources.debian.org/patches/sqlite3/3.32.3-1/20-hurd-locking-style.patch
Upstream status: Not upstreamed.

This patch is needed to get offloading to work.

Sqlite can use simple file locking mode, but that does not work for the Hurd;
a second sqlite process fails with a "locking protocol" error.

See also: https://bugs.debian.org/529734.

diff -purN sqlite-autoconf-3310100/sqlite3.c sqlite-autoconf-3310100-/sqlite3.c
--- sqlite-autoconf-3310100/sqlite3.c	2020-01-27 21:25:19.000000000 +0100
+++ sqlite-autoconf-3310100-/sqlite3.c	2020-07-01 11:50:13.768333806 +0200
@@ -33189,7 +33189,7 @@ SQLITE_PRIVATE const char *sqlite3Opcode
 # include <sys/mman.h>
 #endif
 
-#if SQLITE_ENABLE_LOCKING_STYLE
+#if SQLITE_ENABLE_LOCKING_STYLE || defined(__GNU__)
 /* # include <sys/ioctl.h> */
 # include <sys/file.h>
 # include <sys/param.h>
@@ -35676,7 +35676,7 @@ static int dotlockClose(sqlite3_file *id
 **
 ** Omit this section if SQLITE_ENABLE_LOCKING_STYLE is turned off
 */
-#if SQLITE_ENABLE_LOCKING_STYLE
+#if SQLITE_ENABLE_LOCKING_STYLE || defined(__GNU__)
 
 /*
 ** Retry flock() calls that fail with EINTR
@@ -38586,7 +38586,7 @@ IOMETHODS(
   0                         /* xShmMap method */
 )
 
-#if SQLITE_ENABLE_LOCKING_STYLE
+#if SQLITE_ENABLE_LOCKING_STYLE || defined(__GNU__)
 IOMETHODS(
   flockIoFinder,            /* Finder function name */
   flockIoMethods,           /* sqlite3_io_methods object name */
@@ -41142,6 +41142,8 @@ SQLITE_API int sqlite3_os_init(void){
     UNIXVFS("unix",          autolockIoFinder ),
 #elif OS_VXWORKS
     UNIXVFS("unix",          vxworksIoFinder ),
+#elif defined(__GNU__)
+    UNIXVFS("unix",          flockIoFinder ),
 #else
     UNIXVFS("unix",          posixIoFinder ),
 #endif
@@ -41151,7 +41153,7 @@ SQLITE_API int sqlite3_os_init(void){
 #if OS_VXWORKS
     UNIXVFS("unix-namedsem", semIoFinder ),
 #endif
-#if SQLITE_ENABLE_LOCKING_STYLE || OS_VXWORKS
+#if SQLITE_ENABLE_LOCKING_STYLE || OS_VXWORKS || defined(__GNU__)
     UNIXVFS("unix-posix",    posixIoFinder ),
 #endif
 #if SQLITE_ENABLE_LOCKING_STYLE
oot</a>/<a href='/guix/log/gnu?id=8d7c4b610f0b880a88eb798b36d05933c2e01591'>gnu</a>/<a href='/guix/log/gnu/tests?id=8d7c4b610f0b880a88eb798b36d05933c2e01591'>tests</a>/<a href='/guix/log/gnu/tests/dict.scm?id=8d7c4b610f0b880a88eb798b36d05933c2e01591'>dict.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/tests/dict.scm?id=8d7c4b610f0b880a88eb798b36d05933c2e01591&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2018-10-18 01:12:22 +0200'>2018-10-18</span></td><td><a href='/guix/commit/gnu/tests/dict.scm?id=39d7fdce453b0ca23ecbed72048647debbaa58a6'>services: dhcp-client: Deprecate 'dhcp-client-service' procedure.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-06-13 09:11:45 +0200'>2018-06-13</span></td><td><a href='/guix/commit/gnu/tests/dict.scm?id=c24b15472baaa7ec67d48cbf296bbe5ab727b78f'>tests: Honor the return value of 'start-service'.</a><span class='msg-avail'>...</span></td><td>Clément Lassieur</td></tr>
<tr><td><span title='2018-06-01 13:50:26 +0200'>2018-06-01</span></td><td><a href='/guix/commit/gnu/tests/dict.scm?id=7a4e2eaab34f7fad6951f312203ac0d9dfa3d44a'>marionette: Add 'wait-for-tcp-port'.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-07-20 11:57:13 +0200'>2017-07-20</span></td><td><a href='/guix/commit/gnu/tests/dict.scm?id=8b113790fa3bfd2300c737901ba161f079fedbdf'>tests: Use 'virtual-machine' records instead of monadic procedures.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-04-16 00:48:08 +0200'>2017-04-16</span></td><td><a href='/guix/commit/gnu/tests/dict.scm?id=cbe0af11b2bffb1ef534941ac29d1384c9f09549'>tests: dicod: Bail out if we cannot connect within 20 seconds.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-04-01 00:45:18 +0200'>2017-04-01</span></td><td><a href='/guix/commit/gnu/tests/dict.scm?id=985a8599ed742053b52ac85f753c4feb54af93cb'>tests: Add GNU dicod test.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>