[BUG]: Compiling PTX with undefined extern succeeds and produces empty kernel

Is this a duplicate?

• I confirmed there appear to be no duplicate issues for this bug and that I agree to the Code of Conduct

Type of Bug

Silent Failure

Component

cuda.core

Describe the bug

Attempting to compile PTX with an undefined extern function seems to succeed and produce a cubin with an empty kernel. I am doing this like:

from cuda.core.experimental import Program, ProgramOptions

options = ProgramOptions(arch="sm_75")
program = Program(code, code_type="ptx", options=options)
cubin = program.compile("cubin")

The same PTX compiled with ptxas results in a failure to compile:

$ ptxas -arch sm_75 add_float16.ptx 
ptxas fatal   : Unresolved extern function '_ZplRK6__halfS1__1'

Am I using the Program.compile() interface incorrectly?

How to Reproduce

Run the attached file:

python cudapy.py

This will produce a cubin with an empty kernel, and show ptxas raises an error for the same PTX.

cudapy.py

Expected behavior

An exception or some other error raised by Program.compile()

Operating System

Ubuntu Linux

nvidia-smi output

No response

Start with the attached cudapy.py and the cuda.core.experimental Program.compile("cubin") entry point, then compare its behavior with ptxas on the same PTX. Trace how undefined extern functions are handled during compilation. Done means Program.compile() raises an error or otherwise reports the unresolved extern instead of producing an empty cubin.