yarn install fails at postinstall.sh

[brenzi]

I'm following the README receipt, but I get:

environment:

> node -v
v10.2.0
> sed --version
sed (GNU sed) 4.4

build log

> yarn install
yarn install v1.21.1
warning ../../package.json: No license field
warning package-lock.json found. Your project contains lock files generated by tools other than Yarn. It is advised not to mix package managers in order to avoid resolution inconsistencies caused by unsynchronized lock files. To clear this warning, remove package-lock.json.
[1/4] Resolving packages...
warning Resolution field "[email protected]" is incompatible with requested version "babel-core@^6.0.0"
warning Resolution field "[email protected]" is incompatible with requested version "babel-core@^6.0.0"
[2/4] Fetching packages...
info [email protected]: The platform "linux" is incompatible with this module.
info "[email protected]" is an optional dependency and failed compatibility check. Excluding it from installation.
[3/4] Linking dependencies...
warning " > [email protected]" has incorrect peer dependency "[email protected]".
warning " > [email protected]" has unmet peer dependency "prop-types@^15.6.0".
warning " > [email protected]" has incorrect peer dependency "react-native@>=15.5".
warning " > [email protected]" has unmet peer dependency "asyncstorage-down@>=3.0.0 <5.0.0".
warning "react-navigation > [email protected]" has unmet peer dependency "prop-types@^15.0.0".
warning " > [email protected]" has unmet peer dependency "react-dom@>= 16.3.0".
warning " > [email protected]" has unmet peer dependency "@polkadot/util-crypto@*".
[4/4] Building fresh packages...
$ sh postinstall.sh
postinstall.sh: 2: postinstall.sh: Syntax error: ")" unexpected
error Command failed with exit code 2.
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.

[0xthreebody]

Hello, Now mainly exploring Flutter version: https://github.com/polkawallet-io/polkawallet-flutter
The RN version not updated.
And RN version is slowly.