dotnet/runtime · error · RuntimeError

Unable to find input file in

Error message

Unable to find input file in {original_rsp_filepath}

What it means

Raised inside run_nativeaot() in superpmi.py when scanning the ilc.rsp lines yields no input assembly. The loop sets original_input_filepath to the first line not starting with '-'; if none is found (every line is a flag/option), the rsp has no input file and the script cannot proceed.

Solutions

1. Open the rsp and confirm there is exactly one line that is a bare path to the input assembly (not prefixed with '-').
2. Regenerate the ilc.rsp via the nativeaot build/test infrastructure rather than hand-editing.
3. If the input path legitimately starts with '-', escape or rewrite it per ilc conventions.

Example fix

// before  (rsp contains only flags, no input line)
python superpmi.py collect --nativeaot -ilc_rsps broken.ilc.rsp   # 'Unable to find input file in broken.ilc.rsp'
// after  (ensure rsp has a bare input assembly line, e.g.)
//   --opt:foo
//   ComWrappers.dll
python superpmi.py collect --nativeaot -ilc_rsps fixed.ilc.rsp

with open(rsp_path, encoding="utf-8") as fh:
    lines = fh.read().splitlines()
inputs = [ln for ln in lines if ln.strip() and not ln.lstrip().startswith("-")]
if not inputs:
    raise SystemExit(f"No input assembly line found in {rsp_path}; rsp is malformed")

When it happens

Trigger: An ilc.rsp whose lines all begin with '-' (no bare input assembly path), or an empty/malformed rsp where the input assembly line was stripped or never written.

Common situations: Manually edited rsp missing the input assembly; upstream nativeaot build step that generated an incomplete rsp; whitespace/encoding making the input line start with '-' or be skipped.

Related errors

• Expected a '.ilc.rsp' file for nativeaot, but got
• Tiering options have no effect for nativeaot collections.
• Pass only one tiering option.
• Tiering options have no effect for pmi or crossgen2…
• Unsupported OS.

AI-assisted analysis of dotnet/runtime@60108ba66e (2026-08-10). Data as JSON: /api/errors/333ff11c76c43da1. Report an issue: GitHub.

Appendix: source

Thrown at src/coreclr/scripts/superpmi.py:1209

                    # The contents of the rsp contain many knobs and arguments that represent customer scenarios.
                    # Make a copy of the .ilc.rsp file as we are going to modify it. We do not want to modify the original one.
                    # The modifications include re-writing paths for references, input assembly and the output.
                    # We do this because the current paths in the rsp *may* not exist by the time we want to run ilc.
                    rsp_filepath = os.path.join(self.temp_location, make_safe_filename("nativeaot_" + original_rsp_filepath) + ".rsp")
                    shutil.copyfile(original_rsp_filepath, rsp_filepath)

                    rsp_file = open(rsp_filepath, "r")
                    rsp_contents = rsp_file.readlines()
                    rsp_file.close()

                    original_input_filepath = ""

                    for line in rsp_contents:
                        if not line.startswith("-"):
                            original_input_filepath = line

                    if original_input_filepath == "":
                        raise RuntimeError(f"Unable to find input file in {original_rsp_filepath}")

                    input_filename = os.path.basename(original_input_filepath)

                    # The ilc.rsp files are stored in the 'native' folders, ex: 'ComWrappers/ComWrappers/native/ComWrappers.ilc.rsp'
                    test_native_directory = os.path.abspath(os.path.join(original_rsp_filepath, "..")) # ex: 'ComWrappers/ComWrappers/native/'
                    test_output_directory = os.path.join(test_native_directory, "..") # ex: 'ComWrappers/ComWrappers/'
                    test_directory = os.path.join(test_output_directory, "..") # ex: 'ComWrappers/'

                    # The corresponding input assemblies are in the folder above 'native', ex: 'ComWrappers/ComWrappers/'
                    test_input_filepath = os.path.join(test_output_directory, input_filename)

                    # Blow away references, output, input assembly and directpinvokelist as we are going to use new ones.
                    rsp_file = open(rsp_filepath, "w")
                    def filter_rsp_argument(line):
                        if line.startswith("-r:") or line.startswith("-o:") or not line.startswith("-") or line.startswith("--directpinvokelist:"):
                            return False
                        else:
                            return True

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