Newest fake-cli tries to invoke global Paket even when it's not there

[theimowski]

Description

The issue started appearing for SAFE template:

Starting target 'Build'
/tmp/c99a1e108ebc446f9e1c00aef5b4f45f/src/Server> "/usr/bin/dotnet" build (In: false, Out: false, Err: false)
Copyright (C) Microsoft Corporation. All rights reserved.
p/tmpd26d38b380e34c6da4c7787a31045d51.exec.cmd: paket: not found
/tmp/c99a1e108ebc446f9e1c00aef5b4f45f/.paket/Paket.Restore.targets(120,5): error MSB3073: The command ""paket" restore" exited with code 127. [/tmp/c99a1e108ebc446f9e1c00aef5b4f45f/src/Server/Server.fsproj]

Not sure what's the root cause, but there's some difference between fake-cli 5.13 and 5.15.1.
Using 5.13 as global tool I'm able to build a new safe template project on a fresh box, but when updating fake-cli to 5.15.1 I'm getting above error.

Initially though it was related to extracting new Paket.Restore.targets, but this happens also if I do PAKET_SKIP_RESTORE_TARGETS=true fake build

Repro steps

1. docker run -it microsoft/dotnet:2.2-sdk-alpine
2. apk add --update nodejs yarn
3. dotnet tool install -g fake-cli
4. export PATH="$PATH:/root/.dotnet/tools"
5. mkdir safe && cd safe
6. dotnet new -i SAFE.Template
7. dotnet new safe
8. fake build

If you do then:

1. dotnet tool uninstall -g fake-cli
2. dotnet tool install -g --version 5.13 fake-cli
3. fake build

the project builds fine

[matthid]

But the error clearly talks about Paket.Restore.targets(120,5) I'm not sure this is related to FAKE (not more than the targets extraction topic).
Does dotnet build fail as well (without fake involved)?

[theimowski]

yup, dotnet build fails as well

Right, so might be because older FAKE uses older Paket.Core / Paket.Restore.targets
This is strange though, as when using PAKET_SKIP_RESTORE_TARGETS the targets file stays untouched
I'll try to find changes in Paket.Restore.targets between those two versions of fake

[matthid]

But if you only run dotnet build fake is not involved in any way.

[theimowski]

Correct, this might sound strange but that's actually expected: For SAFE apps we don't want to require full .NET / Mono anymore, hence there's no .paket/paket.exe when creating project from SAFE template. Instead we rely on FAKE global tool to build & run the project.
Recommendation is to use fake build - it does work with FAKE 5.13 but stopped with 5.15.1

[matthid]

Ah so you depend on not needing to run Paket?

[matthid]

I think the issue you run into is pretty much fsprojects/Paket#3608

I'm already in the process of fixing it but doing anything in msbuild is always a fuckup

[matthid]

Thanks for the report I didn't realize FAKE users depend on this 'performance' feature like this.

I guess it would be nice to have an integration test for this scenario

[theimowski]

Ah so you depend on not needing to run Paket?

That's right.
When .net core 3.0 is out we'd ideally use Paket as local tool - I hope that way we can pin to specific version to mitigate breaking changes issues

[matthid]

I'm closing this, as it basically has been addressed, please follow the relevant issues to track the release. In particular, it will be released with #2347 once Paket has merged and released the change. Given that this is indeed a bit nasty I'll probably just release FAKE without any other changes. Which is likely tomorrow evening.

Funnily your comment as at the correct place after all as this was the PR which broke it ;)

[matthid]

@theimowski 5.15.2 should be out in a couple of minutes, please report back if it indeed fixes the problem.

[theimowski]

Thanks @matthid - looks like 5.15.2 fixes the issue 👍