rc-service start hangs when input_file set to fifo pipe

[CelestialCrafter]

Description

When using openrc-run's input_file directive with a fifo pipe at the path specified, doing rc-service <name> start hangs, and only continues the start process after something is written to the pipe.
After using strace, I found that the issue is in an openat call within start-stop-daemon.
Possibly consider using O_NONBLOCK or O_NDELAY for the openat call?

Example

Service:

#!/sbin/openrc-run

name=example
command=sleep
command_args=infinity
command_background="yes"
pidfile="/run/$RC_SVCNAME.pid"
input_file="/var/lib/example-stdin.pipe"

Commands:

mkdir -p /var/lib
mkfifo /var/lib/example-stdin.pipe
rc-service example start
# resolve the hanging
echo bweh > /var/lib/example-stdin.pipe

[N-R-K]

Possibly consider using O_NONBLOCK or O_NDELAY for the openat call?

Right, but you still want the service itself to inherit the fd in blocking mode, yes?

[CelestialCrafter]

My intent is to be able to start the service "normally", and to use the stdin pipe as sort of a debug input channel.