v0.64.1

GR v0.64.1

Diff since v0.64.0

Closed issues:

• "Rerunning build step for GR" caused a new error (#413)
• Precompilation failed when running "] test GR" (#450)

Merged pull requests:

• Add rebuild attempt failsafes and env variable (#417) (@mkitti)
• A few type stability fixes (#452) (@sjkelly)
• Grab bag of inference improvements (#453) (@sjkelly)