fix: add encoding="utf-8" to prompt file open() calls in script_runner (Windows CP950)#607
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edenfunf wants to merge 1 commit intomicrosoft:mainfrom
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fix: add encoding="utf-8" to prompt file open() calls in script_runner (Windows CP950)#607edenfunf wants to merge 1 commit intomicrosoft:mainfrom
edenfunf wants to merge 1 commit intomicrosoft:mainfrom
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…r (Windows CP950) PromptCompiler.compile() and _resolve_prompt_file() open .prompt.md files with plain open() which defaults to the system locale encoding. On Windows systems set to CP950/CP936/CP932 (Chinese/Japanese/Korean), a UTF-8 encoded prompt file containing any multibyte character causes: UnicodeDecodeError: 'cp950' codec can't decode byte 0x8b in position 12 Three open() calls were missing explicit encoding: - compiled_path read in ScriptRunner._execute_script - prompt_path read in PromptCompiler.compile - output_path write in PromptCompiler.compile Adding encoding="utf-8" to all three matches the behaviour of the rest of the codebase and fixes the crash for any non-UTF-8 Windows locale.
danielmeppiel
approved these changes
Apr 7, 2026
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Summary
Fixes a
UnicodeDecodeErrorcrash when reading or writing.prompt.mdfiles on Windows systems with a non-UTF-8 locale encoding.Closes #604.
Root Cause
Three
open()calls inscript_runner.pyrely on the platform default encoding. On Windows with CP950/CP936/CP932, Python cannot decode UTF-8 multi-byte sequences (any CJK character, emoji, or non-ASCII content in a prompt file triggers the error).Changes
src/apm_cli/core/script_runner.py— 3 lines changedScriptRunner._execute_script— read compiled fileopen(compiled_path, "r")open(compiled_path, "r", encoding="utf-8")PromptCompiler.compile— read source promptopen(prompt_path, "r")open(prompt_path, "r", encoding="utf-8")PromptCompiler.compile— write compiled outputopen(output_path, "w")open(output_path, "w", encoding="utf-8")All other
open()andread_text()calls in the codebase already carry an explicitencodingparameter; this brings the remaining three into line.Test Plan
uv run pytest tests/unit/test_script_runner.py -x -v— all tests pass.prompt.mdcontaining CJK characters, runapm run start— noUnicodeDecodeError