#20859 Cryptic error when `package.json` is missing a name Issue created by yjabri Is your feature request related to a problem? Please describe. I was trying out the experimental JavaScript backend and running some "unfriendly" behavior. I've included a minimal reproduction repo to try the following in. Run

pants tailor ::

. It populates

foo/BUILD

with

package_json()

Run

pants tailor ::

again. You'll get

$ pants tailor ::
14:56:17.68 [ERROR] 1 Exception encountered:

Engine traceback:
  in `tailor` goal

KeyError: 'name'

In a non minimal repo I had

package_json()

populate like

package_json(name="foo0")

since I had a python distribution with the same name. Given

KeyError: 'name'

it feels like

tailor

is writing an invalid target to the BUILD file. Also running

pants help targets package_json

doesn't enumerate a

name

field. It took me some time to realize this had nothing to do with the BUILD file but instead that my

package.json

was missing a name. Describe the solution you'd like A more explicit message should be given to the caller that

package.json

needs to have a name the first time

pants tailor

(or any goal that consumes the file) is called. Describe alternatives you've considered Additional context pantsbuild/pants