spec::__str__ places variants next to versions with no spaces. This is not parsing with the GitVersions when the references is assigned (foo@git.[hash]=develop+var1). The error shows up when spack tries to read a spack.lock and is unable to parse the root specs.

An example from a lock file

  "roots": [
    {
      "hash": "pqiebnzqdv7tpuwepniftbdwxoplokag",
      "spec": "[email protected]=master+hypre+openfast arch=linux-None-x86_64"
    },

So there are two potential fixes:

1. Make it so there is always a space between the version and the variants
2. Make the spec parser able to distinguish this as a valid spec.

I've been pursuing path 2, which seems better, but more complicated. Not sure I understand why the parser is hanging onto the these variants when it creates the version.

There is a second bug in that GitVersions fetch calls are not cloning submodules recursively. I want to fix both, but will open a second PR for this issue if it is not a simple fix.

@becker33