Support environment variables for most CLI arguments - #14217
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alexcrichton merged 2 commits intoAug 26, 2026
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* Add a generic `run_cmd` helper to avoid ad-hoc spawning/printing of errors * Consolidate helpers around `Command`. * Remove most usage of `build_wasm` as it's not necessary.
This commit adds support to use environment variables in addition to CLI
flags when configuring `wasmtime` execution. This is applied to all
"option groups" of Wasmtime, such as `-W`, `-S`, `-O`, etc. Options can
be specified as a group:
WASMTIME_OPTIMIZE=opt-level=1,...
or individually:
WASMTIME_OPTIMIZE_OPT_LEVEL=1
CLI configuration overrides environment variables, and environment
variables override file-based configuration. Errors are reported as
usual if any environment variable fails to parse.
alexcrichton
requested review from
fitzgen and
pchickey
and removed request for
a team
August 26, 2026 21:37
pchickey
approved these changes
Aug 26, 2026
pchickey
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Looks good, thank you for cleaning up the cli tests stuff as well
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This commit adds support to use environment variables in addition to CLI
flags when configuring
wasmtimeexecution. This is applied to all"option groups" of Wasmtime, such as
-W,-S,-O, etc. Options canbe specified as a group:
or individually:
CLI configuration overrides environment variables, and environment
variables override file-based configuration. Errors are reported as
usual if any environment variable fails to parse.