Terraform for Digital Ocean crashes: panic: Unary - is only allowed

Terraform 0.6.16 を使用して Apollo DigitalOcean のセットアップを再現し、その後、config/interpolate_walk.go とスタックトレースに示されている vendored HIL parser を通してクラッシュを追跡します。単項マイナスの panic を引き起こす設定式を特定し、そのクラッシュなしにセットアップが完了することを確認します。

Hi,

When trying to setup Apollo on digitalocean terraform crashes. Might be related to https://github.com/hashicorp/terraform/issues/6432 ?

Thanks,
Joost

Crashlog:
`2016/05/26 10:23:15 [INFO] Terraform version: 0.6.16 6e586c89394f5474b6c5f3217a4a75ce80c3fd6c
2016/05/26 10:23:15 [DEBUG] Detected home directory from env var: /root
2016/05/26 10:23:15 [DEBUG] Discovered plugin: atlas = /opt/terraform/terraform-provider-atlas
2016/05/26 10:23:15 [DEBUG] Discovered plugin: aws = /opt/terraform/terraform-provider-aws
2016/05/26 10:23:15 [DEBUG] Discovered plugin: azure = /opt/terraform/terraform-provider-azure
2016/05/26 10:23:15 [DEBUG] Discovered plugin: azurerm = /opt/terraform/terraform-provider-azurerm
2016/05/26 10:23:15 [DEBUG] Discovered plugin: chef = /opt/terraform/terraform-provider-chef
2016/05/26 10:23:15 [DEBUG] Discovered plugin: clc = /opt/terraform/terraform-provider-clc
2016/05/26 10:23:15 [DEBUG] Discovered plugin: cloudflare = /opt/terraform/terraform-provider-cloudflare
2016/05/26 10:23:15 [DEBUG] Discovered plugin: cloudstack = /opt/terraform/terraform-provider-cloudstack
2016/05/26 10:23:15 [DEBUG] Discovered plugin: cobbler = /opt/terraform/terraform-provider-cobbler
2016/05/26 10:23:15 [DEBUG] Discovered plugin: consul = /opt/terraform/terraform-provider-consul
2016/05/26 10:23:15 [DEBUG] Discovered plugin: datadog = /opt/terraform/terraform-provider-datadog
2016/05/26 10:23:15 [DEBUG] Discovered plugin: digitalocean = /opt/terraform/terraform-provider-digitalocean
2016/05/26 10:23:15 [DEBUG] Discovered plugin: dme = /opt/terraform/terraform-provider-dme
2016/05/26 10:23:15 [DEBUG] Discovered plugin: dnsimple = /opt/terraform/terraform-provider-dnsimple
2016/05/26 10:23:15 [DEBUG] Discovered plugin: docker = /opt/terraform/terraform-provider-docker
2016/05/26 10:23:15 [DEBUG] Discovered plugin: dyn = /opt/terraform/terraform-provider-dyn
2016/05/26 10:23:15 [DEBUG] Discovered plugin: fastly = /opt/terraform/terraform-provider-fastly
2016/05/26 10:23:15 [DEBUG] Discovered plugin: github = /opt/terraform/terraform-provider-github
2016/05/26 10:23:15 [DEBUG] Discovered plugin: google = /opt/terraform/terraform-provider-google
2016/05/26 10:23:15 [DEBUG] Discovered plugin: heroku = /opt/terraform/terraform-provider-heroku
2016/05/26 10:23:15 [DEBUG] Discovered plugin: influxdb = /opt/terraform/terraform-provider-influxdb
2016/05/26 10:23:15 [DEBUG] Discovered plugin: librato = /opt/terraform/terraform-provider-librato
2016/05/26 10:23:15 [DEBUG] Discovered plugin: mailgun = /opt/terraform/terraform-provider-mailgun
2016/05/26 10:23:15 [DEBUG] Discovered plugin: mysql = /opt/terraform/terraform-provider-mysql
2016/05/26 10:23:15 [DEBUG] Discovered plugin: null = /opt/terraform/terraform-provider-null
2016/05/26 10:23:15 [DEBUG] Discovered plugin: openstack = /opt/terraform/terraform-provider-openstack
2016/05/26 10:23:15 [DEBUG] Discovered plugin: packet = /opt/terraform/terraform-provider-packet
2016/05/26 10:23:15 [DEBUG] Discovered plugin: postgresql = /opt/terraform/terraform-provider-postgresql
2016/05/26 10:23:15 [DEBUG] Discovered plugin: powerdns = /opt/terraform/terraform-provider-powerdns
2016/05/26 10:23:15 [DEBUG] Discovered plugin: rundeck = /opt/terraform/terraform-provider-rundeck
2016/05/26 10:23:15 [DEBUG] Discovered plugin: softlayer = /opt/terraform/terraform-provider-softlayer
2016/05/26 10:23:15 [DEBUG] Discovered plugin: statuscake = /opt/terraform/terraform-provider-statuscake
2016/05/26 10:23:15 [DEBUG] Discovered plugin: template = /opt/terraform/terraform-provider-template
2016/05/26 10:23:15 [DEBUG] Discovered plugin: terraform = /opt/terraform/terraform-provider-terraform
2016/05/26 10:23:15 [DEBUG] Discovered plugin: tls = /opt/terraform/terraform-provider-tls
2016/05/26 10:23:15 [DEBUG] Discovered plugin: triton = /opt/terraform/terraform-provider-triton
2016/05/26 10:23:15 [DEBUG] Discovered plugin: ultradns = /opt/terraform/terraform-provider-ultradns
2016/05/26 10:23:15 [DEBUG] Discovered plugin: vcd = /opt/terraform/terraform-provider-vcd
2016/05/26 10:23:15 [DEBUG] Discovered plugin: vsphere = /opt/terraform/terraform-provider-vsphere
2016/05/26 10:23:15 [DEBUG] Discovered plugin: chef = /opt/terraform/terraform-provisioner-chef
2016/05/26 10:23:15 [DEBUG] Discovered plugin: file = /opt/terraform/terraform-provisioner-file
2016/05/26 10:23:15 [DEBUG] Discovered plugin: local-exec = /opt/terraform/terraform-provisioner-local-exec
2016/05/26 10:23:15 [DEBUG] Discovered plugin: remote-exec = /opt/terraform/terraform-provisioner-remote-exec
2016/05/26 10:23:15 [DEBUG] Detected home directory from env var: /root
2016/05/26 10:23:15 [DEBUG] Attempting to open CLI config file: /root/.terraformrc
2016/05/26 10:23:15 [DEBUG] File doesn't exist, but doesn't need to. Ignoring.
2016/05/26 10:23:15 [DEBUG] Detected home directory from env var: /root
2016/05/26 10:23:15 [DEBUG] waiting for all plugin processes to complete...
panic: Unary - is only allowed

goroutine 1 [running]:
panic(0xcafb40, 0xc8201e1260)
/opt/go/src/runtime/panic.go:481 +0x3e6
github.com/hashicorp/terraform/vendor/github.com/hashicorp/hil.(_parserParserImpl).Parse(0xc8201e7400, 0x7fa86eb916c0, 0xc8201e81e0, 0x0)
lang.y:133 +0x2168
github.com/hashicorp/terraform/vendor/github.com/hashicorp/hil.parserParse(0x7fa86eb916c0, 0xc8201e81e0, 0x1683a10)
yaccpar:153 +0x9b
github.com/hashicorp/terraform/vendor/github.com/hashicorp/hil.Parse(0xc8201d70c0, 0x12, 0x0, 0x0, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/vendor/github.com/hashicorp/hil/parse.go:27 +0x103
github.com/hashicorp/terraform/config.(_interpolationWalker).Primitive(0xc82015bd90, 0xcafb40, 0xc8201e1060, 0x98, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/config/interpolate_walk.go:116 +0x155
github.com/hashicorp/terraform/vendor/github.com/mitchellh/reflectwalk.walkPrimitive(0xcafb40, 0xc8201e1060, 0x98, 0xfd79c0, 0xc82015bd90, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/vendor/github.com/mitchellh/reflectwalk/reflectwalk.go:186 +0xa9
github.com/hashicorp/terraform/vendor/github.com/mitchellh/reflectwalk.walk(0xcafb40, 0xc8201e1060, 0x98, 0xfd79c0, 0xc82015bd90, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/vendor/github.com/mitchellh/reflectwalk/reflectwalk.go:117 +0x312
github.com/hashicorp/terraform/vendor/github.com/mitchellh/reflectwalk.walkMap(0xcab240, 0xc8201bdd10, 0x15, 0xfd79c0, 0xc82015bd90, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/vendor/github.com/mitchellh/reflectwalk/reflectwalk.go:159 +0x4cf
github.com/hashicorp/terraform/vendor/github.com/mitchellh/reflectwalk.walk(0xcab240, 0xc8201bdd10, 0x15, 0xfd79c0, 0xc82015bd90, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/vendor/github.com/mitchellh/reflectwalk/reflectwalk.go:120 +0x42c
github.com/hashicorp/terraform/vendor/github.com/mitchellh/reflectwalk.Walk(0xcab240, 0xc8201bdd10, 0xfd79c0, 0xc82015bd90, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/vendor/github.com/mitchellh/reflectwalk/reflectwalk.go:70 +0x14c
github.com/hashicorp/terraform/config.(_RawConfig).init(0xc8201cfec0, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/config/raw_config.go:216 +0x11a
github.com/hashicorp/terraform/config.NewRawConfig(0xc8201bdd10, 0xc8201bdd10, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/config/raw_config.go:44 +0x76
github.com/hashicorp/terraform/config.loadResourcesHcl(0xc8201c2580, 0x0, 0x0, 0x0, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/config/loader_hcl.go:457 +0xda1
github.com/hashicorp/terraform/config.(_hclConfigurable).Config(0xc8201aeec0, 0x1043740, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/config/loader_hcl.go:118 +0xd66
github.com/hashicorp/terraform/config.(_importTree).ConfigTree(0xc8201be1c0, 0x2e, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/config/import_tree.go:87 +0x68
github.com/hashicorp/terraform/config.LoadFile(0xc820199cb0, 0x2e, 0x0, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/config/loader.go:44 +0x80
github.com/hashicorp/terraform/config.LoadDir(0xc820014034, 0x26, 0x11, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/config/loader.go:91 +0x38c
github.com/hashicorp/terraform/config/module.NewTreeModule(0x0, 0x0, 0xc820014034, 0x26, 0x0, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/config/module/tree.go:40 +0x41
github.com/hashicorp/terraform/command.(_Meta).Context(0xc82018a0f0, 0xc820014034, 0x26, 0x0, 0x0, 0x1, 0x0, 0x0, 0xc, 0x0, ...)
/opt/gopath/src/github.com/hashicorp/terraform/command/meta.go:148 +0x509
github.com/hashicorp/terraform/command.(_GetCommand).Run(0xc82018a0f0, 0xc82000a270, 0x0, 0x0, 0xc820109920)
/opt/gopath/src/github.com/hashicorp/terraform/command/get.go:54 +0x3b1
github.com/hashicorp/terraform/vendor/github.com/mitchellh/cli.(_CLI).Run(0xc8200ba600, 0xc820199380, 0x0, 0x0)
/opt/gopath/src/github.com/hashicorp/terraform/vendor/github.com/mitchellh/cli/cli.go:153 +0x5ee
main.wrappedMain(0x0)
/opt/gopath/src/github.com/hashicorp/terraform/main.go:142 +0xb05
main.realMain(0x0)
/opt/gopath/src/github.com/hashicorp/terraform/main.go:78 +0xa10
main.main()
/opt/gopath/src/github.com/hashicorp/terraform/main.go:21 +0x18
`