Mutations not compiling: `Option.Option_unwrap_error`

[jessep]

I'm getting some inscrutable errors. When I paste the following example from the README:

module SignUpQuery = [%graphql
  {|
mutation($name: String!, $email: String!, $password: String!) {
  signUp(email: $email, email: $email, password: $password) @bsVariant {
    user {
      name
    }

    errors {
      field
      message
    }
  }
}
|}
];

I get the following output:

>>>> Start compiling
Rebuilding since [ [ 'change', 'Query.re' ] ]
ninja: Entering directory `lib/bs'
[1/2] Building client/src/Query.mlast
FAILED: client/src/Query.mlast
/Users/jessep/Dropbox/Code/movement/node_modules/bs-platform/lib/bsc.exe -pp "/Users/jessep/Dropbox/Code/movement/node_modules/bs-platform/lib/refmt.exe --print binary" -ppx '/Users/jessep/Dropbox/Code/movement/node_modules/bs-platform/lib/reactjs_jsx_ppx_2.exe'  -ppx /Users/jessep/Dropbox/Code/movement/node_modules/graphql_ppx/ppx -w -30-40+6+7+27+32..39+44+45+101 -bs-suffix -nostdlib -I '/Users/jessep/Dropbox/Code/movement/node_modules/bs-platform/lib/ocaml' -no-alias-deps -color always -c -o client/src/Query.mlast -bs-syntax-only -bs-binary-ast -impl /Users/jessep/Dropbox/Code/movement/client/src/Query.re
Option.Option_unwrap_error
File "/Users/jessep/Dropbox/Code/movement/client/src/Query.re", line 1, characters 0-0:
Error: Error while running external preprocessor
Command line: /Users/jessep/Dropbox/Code/movement/node_modules/graphql_ppx/ppx '/var/folders/5x/w6vwvtzn1ts97f42_0kf74200000gn/T/camlppx803ef4' '/var/folders/5x/w6vwvtzn1ts97f42_0kf74200000gn/T/camlppx4a607c'

ninja: error: rebuilding 'build.ninja': subcommand failed
>>>> Finish compiling(exit: 1)

I have no idea what to do here. Here are versions of bs-platform and graphql_ppx From my package.json

 "bs-platform": "^3.1.5",
  "graphql_ppx": "^0.2.4"

[jessep]

I should also mention that non-mutation queries seem to work as expected.

[mhallin]

What does your schema look like; does it contain a signUp mutation with those fields?

It's definitely a bug that the error message is an Option_unwrap_error, so I'm a bit curious as to how your schema looks to produce this bug.

[jessep]

It was in fact related to the schema. I didn't have any mutations defined in the schema, and was confused because all sorts of other stuff that wasn't in the schema was still giving me proper errors.