firefox-l10n fails to build with fetch_locale: 1: set: Illegal option -o pipefail

🐞 Bug Report

Reproduction steps

Run a desktop build (e.g. linux-aarch64, but this isn't platform-specific) on Ubuntu 24.04.3 LTS.

Expected behaviour

firefox-l10n should build.

Actual behaviour

firefox-l10n fails to build with error fetch_locale: 1: set: Illegal option -o pipefail. This happens because firefox-l10n is not built in a container, fetch_locale as a script has no shebang, Ubuntu 24.04.3 runs it with dash, and dash does not support -o pipefail.

Host Environment

Ubuntu 24.04.3 LTS.