Invalid CIL/Null reference exception on call to paket.exe

Description

For some reason our CI for Hopac started failing with:

System.NullReferenceException: Object reference not set to an instance of an object from https://travis-ci.org/Hopac/Hopac/jobs/430883446#L1829

…and…

/home/travis/build/Hopac/Hopac/.paket/Paket.Restore.targets(81,5): error MSB3073: The command “mono --runtime=v4.0.30319 “/home/travis/build/Hopac/Hopac/.paket/paket.exe” restore” exited with code 1. [/home/travis/build/Hopac/Hopac/Benchmarks/ThreadRing/ThreadRing.fsproj]

For code https://github.com/Hopac/Hopac/commits/master

Repro steps

Please provide the steps required to reproduce the problem

language: csharp
sudo: false  # use the new container-based Travis infrastructure
install:
  - export FrameworkPathOverride=$(dirname $(which mono))/../lib/mono/4.7.1/
env: CONFIGS=Release
os: linux
dotnet: 2.1.402

matrix:
  include:
    - mono: latest
  exclude:
    - env: CONFIGS=Release

script: ./run tests

for the above code base.

Expected behavior

Not to crash.

Actual behavior

Internal error somewhere in mono 5.14.

Known workarounds

Since we don’t have any caches declared in the travis file, I don’t see why this started happening and is happening on every run now. I can run it all locally just fine with mono 5.14.

[matthid]

dotnet tool install --tool-path ".paket" Paket --version 5.182.0-alpha001 --add-source https://api.nuget.org/v3/index.json

probably more stable than running with mono. Thanks to @enricosada

[haf]

Closing because this issue is not actionable from Paket’s side AFAIK.