From 7485e9c9652c8add0a10302b4a4076148f3b626c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Kr=C3=B6ning?= <mkroening@posteo.net>
Date: Wed, 5 Jul 2023 12:49:35 +0200
Subject: [PATCH] `unix::init`: Handle `ENOSYS` from `poll` on Unikraft.
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Signed-off-by: Martin Kröning <martin.kroening@eonerc.rwth-aachen.de>
---
 library/std/src/sys/unix/mod.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/library/std/src/sys/unix/mod.rs b/library/std/src/sys/unix/mod.rs
index 326f1481e1918..9d52f414574a7 100644
--- a/library/std/src/sys/unix/mod.rs
+++ b/library/std/src/sys/unix/mod.rs
@@ -110,6 +110,11 @@ pub unsafe fn init(argc: isize, argv: *const *const u8, sigpipe: u8) {
             while libc::poll(pfds.as_mut_ptr(), 3, 0) == -1 {
                 match errno() {
                     libc::EINTR => continue,
+                    #[cfg(target_vendor = "unikraft")]
+                    libc::ENOSYS => {
+                        // Not all configurations of Unikraft enable `LIBPOSIX_EVENT`.
+                        break 'poll;
+                    }
                     libc::EINVAL | libc::EAGAIN | libc::ENOMEM => {
                         // RLIMIT_NOFILE or temporary allocation failures
                         // may be preventing use of poll(), fall back to fcntl