Panic when module schemas change

[wesbillman]

When running main with ftl dev --recreate after the modules are deployed, in a new terminal window run ftl schema get --watch. Then, make a change to echo.go to modify the module triggering a possible schema change (I changed "Hello, %s!!! It is %s!" to "Hellos, %s!!! It is %s!"). Save the file and the ftl schema get --watch will panic.

I think this is leading to other schema update errors elsewhere, but this was the easiest way I could find to reproduce.

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x2 addr=0x30 pc=0x102f0e238]

goroutine 1 [running]:
github.com/TBD54566975/ftl/backend/schema.ModuleFromProto(0x140003f3940?)
	/Users/wesbillman/dev/ftl/backend/schema/module.go:235 +0x18
main.(*getSchemaCmd).Run(0x10579da38, {0x10474f098, 0x14000a82210}, {0x104768390, 0x1400092fd00})
	/Users/wesbillman/dev/ftl/frontend/cli/cmd_schema_get.go:40 +0x1cc
reflect.Value.call({0x104424fc0?, 0x10579da38?, 0x14000671918?}, {0x103c68b1f, 0x4}, {0x14000a82420, 0x2, 0x1031b2028?})
	/Users/wesbillman/Library/Caches/hermit/pkg/go-1.23.1/src/reflect/value.go:581 +0x97c
reflect.Value.Call({0x104424fc0?, 0x10579da38?, 0x14000671a18?}, {0x14000a82420?, 0x10471e080?, 0x14000671950?})
	/Users/wesbillman/Library/Caches/hermit/pkg/go-1.23.1/src/reflect/value.go:365 +0x94
github.com/alecthomas/kong.callFunction({0x104424fc0?, 0x10579da38?, 0x14000671b78?}, 0x14000a82360)
	/Users/wesbillman/go/pkg/mod/github.com/alecthomas/[email protected]/callbacks.go:98 +0x390
github.com/alecthomas/kong.(*Context).RunNode(0x140009a6c80, 0x140004fc2d0, {0x14000671e80, 0x1, 0x1400092fc80?})
	/Users/wesbillman/go/pkg/mod/github.com/alecthomas/[email protected]/context.go:798 +0x604
github.com/alecthomas/kong.(*Context).Run(0x140001a2c30?, {0x14000671e80?, 0x1400052c208?, 0x3?})
	/Users/wesbillman/go/pkg/mod/github.com/alecthomas/[email protected]/context.go:823 +0x138
main.main()
	/Users/wesbillman/dev/ftl/frontend/cli/main.go:128 +0x45c