X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/3ecab1575ef1f45a5e7cd3c48cd937ffa8eb0ad9..ac7a78c5a176d65837fe4d0487d68b349739a126:/src/OS/os.h-Linux

diff --git a/src/OS/os.h-Linux b/src/OS/os.h-Linux
index fe4eaa6c7..3fead17d7 100644
--- a/src/OS/os.h-Linux
+++ b/src/OS/os.h-Linux
@@ -57,4 +57,16 @@ extern struct ip_address_item *os_find_running_interfaces_linux(void);
 
 #endif /* __linux__ */
 
+/* Some folks running "unusual" setups with very old libc environments have
+found that _GNU_SOURCE=1 before <features.h> is not sufficient to define some
+constants needed for 64-bit arithmetic.  If you encounter build errors based
+on LLONG_MIN being undefined and various other escape hatches have not helped,
+then change the 0 to 1 in the next block. */
+
+#if 0
+# define LLONG_MIN LONG_LONG_MIN
+# define LLONG_MAX LONG_LONG_MAX
+#endif
+
+
 /* End */