wasm32-unknown-unknown causes deploy fail

[JJJ-Mo3]

wasm32-unknown-unknown doesn't create the _start export, which is needed for deploy -- this creates a catch-22 where wasm32-unknown-unknown is a requirement for build, but causes deploy to fail

[jeffcharles]

Do you have a shopify.extension.toml file with at least one extensions.targeting subtable? And do all extensions.targeting subtables define an export key?

Would you mind sharing how you have the entrypoint for your Function defined?

For context, a _start export is not necessary for deploy if you define at least one exported Rust function name for your [[extensions.targeting]] subtable in your shopify.extension.toml.

For example, if you have a shopify.extension.toml that looks like:

api_version = "2025-07"

[[extensions]]
...

[[extensions.targeting]]
target = "cart.validations.generate.run"
input_query = "src/cart_validations_generate_run.graphql"
export = "cart_validations_generate_run"

[extensions.build]
command = "cargo build --target=wasm32-unknown-unknown --release"
path = "target/wasm32-unknown-unknown/release/cart-checkout-validation.wasm"
watch = ["src/**/*.rs"]

And a Rust file that looks like:

use super::schema;
use shopify_function::prelude::*;
use shopify_function::Result;

#[shopify_function]
fn cart_validations_generate_run(
    input: schema::cart_validations_generate_run::Input,
) -> Result<schema::CartValidationsGenerateRunResult> {
    ...
}

This will deploy without an exported _start function.

[JJJ-Mo3]

you can close it out - I was missing the export in my shopify.extension.toml :facepalm: thanks!!

…

On Mon, Oct 6, 2025 at 12:07 PM Jeffrey Charles ***@***.***> wrote: *jeffcharles* left a comment (Shopify/shopify-function-rust#173) <#173 (comment)> Do you have a shopify.extension.toml file with at least one extensions.targeting subtable? And do all extensions.targeting subtables define an export key? Would you mind sharing how you have the entrypoint for your Function defined? For context, a _start export is not necessary for deploy if you define at least one exported Rust function name for your [[extensions.targeting]] subtable in your shopify.extension.toml. For example, if you have a shopify.extension.toml that looks like: api_version = "2025-07" [[extensions]]... [[extensions.targeting]]target = "cart.validations.generate.run"input_query = "src/cart_validations_generate_run.graphql"export = "cart_validations_generate_run" [extensions.build]command = "cargo build --target=wasm32-unknown-unknown --release"path = "target/wasm32-unknown-unknown/release/cart-checkout-validation.wasm"watch = ["src/**/*.rs"] And a Rust file that looks like: use super::schema;use shopify_function::prelude::*;use shopify_function::Result; #[shopify_function]fn cart_validations_generate_run( input: schema::cart_validations_generate_run::Input,) -> Result<schema::CartValidationsGenerateRunResult> { ...} This will deploy without an exported _start function. — Reply to this email directly, view it on GitHub <#173 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AEHSDUEG2TYHUFW23DAT7L33WK4YLAVCNFSM6AAAAACILVTGX2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTGNZTGQ2TEOBRHA> . You are receiving this because you authored the thread.Message ID: ***@***.***>