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 */
uix/diff/gnu/system/uuid.scm?id=3c181f97658bca5a8223d081e9a22e9c971233a0'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/system/uuid.scm'>
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<div class='path'>path: <a href='/guix/log/?id=3c181f97658bca5a8223d081e9a22e9c971233a0'>root</a>/<a href='/guix/log/gnu?id=3c181f97658bca5a8223d081e9a22e9c971233a0'>gnu</a>/<a href='/guix/log/gnu/system?id=3c181f97658bca5a8223d081e9a22e9c971233a0'>system</a>/<a href='/guix/log/gnu/system/uuid.scm?id=3c181f97658bca5a8223d081e9a22e9c971233a0'>uuid.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/system/uuid.scm?id=3c181f97658bca5a8223d081e9a22e9c971233a0&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-09-23 18:17:17 +0200'>2021-09-23</span></td><td><a href='/guix/commit/gnu/system/uuid.scm?id=90604348e14913da48327da05113d7da8ae7655a'>uuid: Support XFS.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/system/uuid.scm (string-&gt;xfs-uuid): New procedure.
(%uuid-parsers, %uuid-printers): Add ‘xfs’ file system type.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-11-07 13:40:46 +0100'>2020-11-07</span></td><td><a href='/guix/commit/gnu/system/uuid.scm?id=e87471dc510bc393e3306fba86f919dc6bf89b7b'>uuid: Add support for bcachefs.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/system/uuid.scm (string-&gt;bcachefs-uuid): New exported procedure.
(%uuid-parsers, %uuid-printers): Add the ‘bcachefs’ file system type.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2020-07-26 18:35:10 +0200'>2020-07-26</span></td><td><a href='/guix/commit/gnu/system/uuid.scm?id=675e56221e3dfc58cac94bf30835f16a9c41d530'>file-systems: Add NTFS support.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/system/uuid.scm (%ntfs-endianness): New macro,
(ntfs-uuid-&gt;string): new procedure,
(%ntfs-endianness): new variable,
(string-&gt;ntfs-uuid): new exported procedure,
(%uuid-parsers): add NTFS support,
(%uuid-printers): add NTFS support.
* gnu/build/file-systems.scm (%ntfs-endianness): New macro,
(ntfs-superblock?, read-ntfs-superblock, ntfs-superblock-uuid,
check-ntfs-file-system): new procedure,
(%partition-uuid-readers): add NTFS support,
(check-file-system): add NTFS support.
</span></span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2020-06-18 23:24:37 -0400'>2020-06-18</span></td><td><a href='/guix/commit/gnu/system/uuid.scm?id=04a4af6dd4fbfcfc564eac5eafe647b192ba3a8f'>uuid: Prevent a loop on invalid arguments.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/system/uuid.scm (uuid=?): Use type predicates in the fallback case to
prevent looping on invalid arguments.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2020-01-03 13:54:13 +0100'>2020-01-03</span></td><td><a href='/guix/commit/gnu/system/uuid.scm?id=43c4d27cdfed5ce98ecd4ce48fcd43e188e5a3aa'>uuid: Add support for JFS.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/system/uuid.scm (string-&gt;jfs-uuid): New procedure.
(%uuid-parsers, %uuid-printers): Add ‘jfs’ file system type.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2019-05-07 12:18:44 +0200'>2019-05-07</span></td><td><a href='/guix/commit/gnu/system/uuid.scm?id=6c5790a2faf8ffc401e43b13425a707394e40874'>uuid: 'fat-uuid-&gt;string' preserves leading zeros.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;https://bugs.gnu.org/35582&gt;.
Reported by sirgazil &lt;sirgazil@zoho.com&gt;.

Previously, leading zeros would be removed, leading to an "invalid"
UUID:

  (uuid-&gt;string (uuid "00CA-050E" 'fat32))
  ⇒ "CA-50E"
  (string-&gt;uuid "CA-50E" 'fat32)
  ⇒ #f

* gnu/system/uuid.scm (fat-uuid-&gt;string): Pad digits with zeros.
* tests/uuid.scm ("uuid, FAT32, leading zeros preserved"): New test.
</span></span></td><td>Ludovic Courtès</td></tr>