Point read-data at the resolved data dir, not a relative token

[wormeyman]

build_config_ini emitted read-data=__PATH__executable__/../data on every platform. That token is correct for a macOS bundle, where the binary sits at Contents/MacOS/factorio and data is one level up. Windows and Linux put the binary at bin/x64/, so the same token resolves to bin/data and the game refuses to start.

Measured on a real 2.1.14 Windows install, 2026-08-17

read-data=__PATH__executable__/../data     -> exit 1
    "There is no package core in V:/factorio-2.1.14/bin/data"
read-data=__PATH__executable__/../../data  -> exit 0

The fix

resolve_layout already works the data directory out correctly for every layout it supports. That value was simply not being used. So take it as a parameter and emit it absolute.

Branching the token on layout would also work, but it re-derives here what resolve_layout has already established, and a second copy of that knowledge is a second chance to get it wrong. An absolute path has no layout to know about, and is what both the macOS and Windows captures used on the day this was measured, producing identical dump bytes (sha256 acc944e6...).

Windows accepts either slash style, so Path::display() emitting native backslashes needs no rewriting: V:\factorio-2.1.14\data and V:/factorio-2.1.14/data both exit 0 and dump identical bytes. Measured, since a backslash in an ini value is the kind of thing that gets eaten.

Why no test caught it

The suite only ever ran on macOS, which is the one layout the token was right for. This came out of a separate experiment asking whether --dump-data is byte-identical across architectures. It is - same build, mac-arm64 and win64 both produce sha256 acc944e6... from byte-identical inputs. But going to look turned up this, which is the same platform blind spot in a place nobody was checking.

The new test asserts the token is absent for a bundle path, a Linux path and a Windows path, so that blind spot cannot silently return.

Checks

cargo fmt --all -- --check, cargo clippy --all-targets -- -D warnings, and cargo test --all-targets all pass: 113 unit tests plus 6 install-gated tests. The byte-for-byte fixture gate still passes.

🤖 Generated with Claude Code

https://claude.ai/code/session_01P9FADuTnjE7SFEQWnpNhfc