Release failing with "No such file or directory"

I have an application that is getting an error during deploy. It previously deployed fine but I am adding a custom binary to the release container. I am pretty sure my binary is building ok in the container, and in any case I have debug statements in my app for when it can’t find the binary, so I don’t know for sure if this is the cause.

The error I get is:

Command: /app/bin/mkrand eval Mkrand.Release.migrate
	 Starting instance
	 Configuring virtual machine
	 Pulling container image
	 Unpacking image
	 Preparing kernel init
	 Configuring firecracker
	 Starting virtual machine
	 Starting init (commit: 9445492)...
	 Running: `/app/bin/mkrand eval Mkrand.Release.migrate` as nobody
	 Error: UnhandledIoError(Os { code: 2, kind: NotFound, message: "No such file or directory" })
	 [    0.065147] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000100
	 [    0.066146] CPU: 0 PID: 1 Comm: init Not tainted 5.12.2 #1
	 [    0.066896] Call Trace:
	 [    0.067216]  dump_stack+0x63/0x7e
	 [    0.067646]  panic+0xf3/0x2a1

I have a debug statement on my application’s Release.migrate function but I don’t see it in the output so I am not sure if that is what is crashing it.
I am open to ideas about what to look for.

This is most likely a missing executable, or an executable not marked as executable. Probably /app/bin/mkrand.

How are you adding the binary? mkrand is your mix release name, right?

sorry I just now saw your response, I went off and tried it on another platform and forgot about this, but now I came back to fly and I am having a variant of the same problem, there is no /app/bin/<my_app>. I posted the new problem under another user that was having a similar issue.