Cannot set arrays of objects in genesis configuration

[zdave-parity]

Issue Description

Take for example the following network definition:

[relaychain]
default_image = "{{ZOMBIENET_INTEGRATION_TEST_IMAGE}}"
default_command = "substrate"
chain = "local"

  [[relaychain.genesis.runtime.mixnet.mixnodes]]
  kx_public = [94, 54, 117, 145, 86, 22, 29, 138, 0, 199, 166, 22, 250, 241, 183, 220, 208, 104, 51, 42, 12, 155, 229, 246, 228, 114, 202, 82, 127, 19, 72, 41]
  peer_id = [152, 0, 36, 8, 1, 18, 32, 213, 191, 74, 63, 204, 231, 23, 176, 56, 139, 204, 39, 73, 235, 193, 72, 173, 153, 105, 178, 63, 69, 238, 27, 96, 95, 213, 135, 120, 87, 106, 196]
  external_addresses = []

  [[relaychain.nodes]]
  name = "alice"

This tries to set an array in the genesis configuration, runtime.mixnet.mixnodes. Currently this fails with the error TypeError: Cannot convert object to primitive value. The issue appears to be this line in chainSpec.ts:

debug(`[ ${key}: ${obj2[key]} ]`);

Commenting it out fixes things.

Steps to reproduce the issue

1. Build the Substrate kitchen-sink node on my mixnet branch (sorry, I'm not aware of any existing pallets which have an array-of-objects in their genesis configuration).
2. Create a network.toml file with the above contents.
3. Run node packages/cli/dist/cli.js --provider native spawn network.toml.

Describe the results you received

Zombienet prints the following error:

Fail to customize genesis

 Unexpected error:  	 TypeError: Cannot convert object to primitive value

The final chain spec local-plain.json has an empty mixnodes array.

Describe the results you expected

Zombienet should successfully launch the network without printing any errors. The final chain spec local-plain.json should not have an empty mixnodes array.

Zombienet version

33a5f83

Provider

Native

Provider version

Substrate kitchen-sink node, built on my mixnet branch.

Upstream Latest Release

Yes

[pepoviola]

Hi @zdave-parity thanks for reporting, we will check and fix this bug asap.

Thx!