Better error messages for "invariant violated: multiple results when describing installed package" #1408
Description
When running stack install below with a custom snapshot, I get the error that I pasted below. It'd be great if the error was more explicit about what exactly went wrong, and perhaps suggestions as far as how to move forward:
$ stack install fr
yesod-persistent-1.4.0.3: configure
yesod-persistent-1.4.0.3: build
kan-extensions-4.2.3: configure
kan-extensions-4.2.3: build
yesod-persistent-1.4.0.3: copy/register
yesod-form-1.4.4.1: configure
yesod-form-1.4.4.1: build
kan-extensions-4.2.3: copy/register
lens-4.12.3: configure
lens-4.12.3: build
pointed-4.2.0.2: configure
pointed-4.2.0.2: build
pointed-4.2.0.2: copy/register
vector-instances-3.3.1: configure
vector-instances-3.3.1: build
vector-instances-3.3.1: copy/register
mono-traversable-0.9.3: configure
mono-traversable-0.9.3: build
yesod-form-1.4.4.1: copy/register
lens-4.12.3: copy/register
mono-traversable-0.9.3: copy/register
Progress: 7/18singleBuild: invariant violated: multiple results when describing installed package
The code that throws this is here: https://github.com/commercialhaskell/stack/blob/master/src/Stack/Build/Execute.hs#L1110
Also, any advice on how to move past this?