HP/UX uses EWOULDBLOCK instead of EAGAIN
diff --git a/src/os/unix/ngx_errno.h b/src/os/unix/ngx_errno.h
index ddc2b27..e1891e7 100644
--- a/src/os/unix/ngx_errno.h
+++ b/src/os/unix/ngx_errno.h
@@ -30,7 +30,6 @@
#define NGX_EINVAL EINVAL
#define NGX_ENOSPC ENOSPC
#define NGX_EPIPE EPIPE
-#define NGX_EAGAIN EAGAIN
#define NGX_EINPROGRESS EINPROGRESS
#define NGX_EADDRINUSE EADDRINUSE
#define NGX_ECONNABORTED ECONNABORTED
@@ -48,6 +47,11 @@
#define NGX_EILSEQ EILSEQ
#define NGX_ENOMOREFILES 0
+#if (__hpux__)
+#define NGX_EAGAIN EWOULDBLOCK
+#else
+#define NGX_EAGAIN EAGAIN
+#endif
#define ngx_errno errno