examples: basic tinygo example fails with tinygo 0.35.0

[mauriciovasquezbernal]

Describe the bug
Running the basic example when compiled with tinygo v0.35.0 fails.

To Reproduce

1. Compile the example with tinygo v0.35.0

$ tinygo version
tinygo version 0.35.0 linux/amd64 (using go version go1.23.4 and LLVM version 18.1.8)

$ tinygo build -o add.wasm -target=wasi add.go

2. Run the example

$ go run . 5 8
2025/01/07 15:10:25 failed to call add: module closed with exit_code(0)
panic: failed to call add: module closed with exit_code(0)

goroutine 1 [running]:
log.Panicf({0x69ad7b?, 0x6f2e30?}, {0xc000587f28?, 0xc0003b3270?, 0x1bb41?})
        /usr/local/go/src/log/log.go:439 +0x65
main.main()
        /home/mauriciov/kinvolk/ebpf/wazero/examples/basic/add.go:60 +0x2f9
exit status 2

Expected behavior

Example should run fine.

Environment (please complete the relevant information):

• Go version: 1.23.4
• wazero Version: 610c202
• Host architecture: amd64
• Runtime mode: -

Additional context

It's a duplicated of #2352 which was closed because "It's not a bug - see the error message saying your module exited with zero.". If it's not a bug, then the sample code on this repository should be updated. I tried using ExitError, but now it crashes in another place:

diff --git a/examples/basic/add.go b/examples/basic/add.go
index 93658e9a..a4eedd70 100644
--- a/examples/basic/add.go
+++ b/examples/basic/add.go
@@ -11,6 +11,7 @@ import (

        "github.com/tetratelabs/wazero"
        "github.com/tetratelabs/wazero/imports/wasi_snapshot_preview1"
+       "github.com/tetratelabs/wazero/sys"
 )

 // addWasm was generated by the following:
@@ -57,9 +58,15 @@ func main() {
        add := mod.ExportedFunction("add")
        results, err := add.Call(ctx, x, y)
        if err != nil {
-               log.Panicf("failed to call add: %v", err)
+               if exitErr, ok := err.(*sys.ExitError); ok && exitErr.ExitCode() == 0 {
+                       // Exited with code 0. Nothing to worry about.
+               } else {
+                       log.Panicf("failed to call add: %v", err)
+               }
        }

+       fmt.Printf("results is %v\n", results)
+
        fmt.Printf("%d + %d = %d\n", x, y, results[0])
 }

$ go run . 5 8
results is []
panic: runtime error: index out of range [0] with length 0

goroutine 1 [running]:
main.main()
        /home/mauriciov/kinvolk/ebpf/wazero/examples/basic/add.go:70 +0x478
exit status 2

I bisected tinygo and it happens from tinygo-org/tinygo@ceb7891 if that's relevant somehow.

[robbyt]

If anyone needs a MacOS workaround to easily install TinyGo 0.34.0:

• brew uninstall tinygo
• Download the previous brew formula directly from here: https://github.com/tinygo-org/homebrew-tools/blob/v0.34.0/tinygo.rb
• brew install ./tinygo.rb

Then use pin to prevent it from being updated by brew upgrade:

• brew pin tinygo