This patch is borrowed from Debian's patches for plink

Author: Peter Green <plugwash@p10link.net>
Puropose: Fallback to endian.h if all else fails on 64bit machines
Closes: #528659
Forwarded: Shaun Purcell <plink@chgr.mgh.harvard.edu>
License: same as plink itself.
===================================================================
--- plink-1.06.orig/Rsrv.h	2009-05-15 03:35:29.000000000 +0100
+++ plink-1.06/Rsrv.h	2009-05-15 03:35:41.000000000 +0100
@@ -313,7 +313,18 @@
 #define __BIG_ENDIAN__ 1
 #define SWAPEND 1
 #elif ! defined Win32 /* Windows is little-endian is most cases, anywhere else we're stuck */
-#error "Cannot determine endianness. Make sure config.h is included or __{BIG|LITTLE}_ENDIAN__ is defined ."
+  //try endian.h before we finally bail out
+  #include <endian.h>
+  #if __BYTE_ORDER == __LITTLE_ENDIAN
+    #warning using little endian based on information from endian.h
+    #define __LITTLE_ENDIAN__ 1
+  #elif __BYTE_ORDER == __BIG_ENDIAN
+    #warning using big endian based on information from endian.h
+    #define __BIG_ENDIAN__ 1
+    #define SWAPEND 1
+  #else    
+    #error "Cannot determine endianness. Make sure config.h is included or __{BIG|LITTLE}_ENDIAN__ is defined ."
+  #endif    
 #endif
 
 /* FIXME: all the mess below needs more efficient implementation - the current one is so messy to work around alignment problems on some platforms like Sun and HP 9000 */
.scm?id=8520f00d6989ff5ab22755a97dfcfd0375f6b5ca'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/tests/cache.scm'>
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<div class='path'>path: <a href='/guix/log/?id=8520f00d6989ff5ab22755a97dfcfd0375f6b5ca'>root</a>/<a href='/guix/log/tests?id=8520f00d6989ff5ab22755a97dfcfd0375f6b5ca'>tests</a>/<a href='/guix/log/tests/cache.scm?id=8520f00d6989ff5ab22755a97dfcfd0375f6b5ca'>cache.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/tests/cache.scm?id=8520f00d6989ff5ab22755a97dfcfd0375f6b5ca&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-06-04 12:04:23 +0200'>2022-06-04</span></td><td><a href='/guix/commit/tests/cache.scm?id=104b4e25ab7da5697f2f6f1ddfdd4955f05afece'>cache: Catch invalid 'last-expiry-cleanup'.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;http://issues.guix.gnu.org/55638&gt;.

* guix/cache.scm (maybe-remove-expired-cache-entries)[last-expiry-date]:
Use 'get-string-all' + 'string-&gt;number' instead of 'read'; ignore
invalid numbers.
* tests/cache.scm ("maybe-remove-expired-cache-entries, empty cache")
("maybe-remove-expired-cache-entries, corrupted cache"): New tests.

Co-authored-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>zimoun</td></tr>
<tr><td><span title='2020-03-22 16:49:47 +0100'>2020-03-22</span></td><td><a href='/guix/commit/tests/cache.scm?id=9acacb71c958218fd69cf0fb9df0b439a980a0f2'>Remove workaround for 'time-monotonic' in Guile 2.2.2.</a><span class='msg-avail'>...<span class='msg-tooltip'>This is a followup to e688c2df3924423b67892cc9939ca099c729d1cb.

* build-aux/hydra/evaluate.scm &lt;top level&gt;: Remove 'time-monotonic'
definition.
* guix/cache.scm: Likewise.
* guix/progress.scm: Likewise.
* guix/scripts/substitute.scm: Likewise.
* guix/scripts/weather.scm: Likewise.
* tests/cache.scm: Likewise.
</span></span></td><td>Ludovic Courtès</td></tr>