fix: enable paths with junction inside windows

[blaubaer]

This is a workaround for the behavior of filepath.EvalSymlinks which errors with syscall.ENOTDIR if the provided path does include a Junction on Windows. Junctions can happen if a volume is mounted inside another drive as a subdirectory, for example. This can be usually happen if used with the feature Dev Drives and this replaces existing directories.

See original issue golang/go#40180. This issue is currently unresolved, and the ticket is leaning towards leaving this to the interpretation of the evaluating code rather than handling it within filepath.EvalSymlinks itself.

As syscall.ENOTDIR is only returned when calling filepath.EvalSymlinks on Windows if a part of the presented path is a Junction and nothing before was a symlink, we simply treat this as NOT symlink, because a symlink above the Junction does not make sense at all.

[boring-cyborg]

Hey, thank you for opening your first Pull Request !

[CLAassistant]

All committers have signed the CLA.

[blaubaer]

@ldez I really tried to add tests at first. Because of the required complexity of the system requirements, like having a junction that needs to be created by the test itself and so, I tried to make the impact as simple as possible instead and tested it on my own machine instead.

[ldez]

Have to try if winsymlink=1 + go1.23 changes the behavior?

[blaubaer]

winsymlink=0 works on go1.23, because from go1.23 on this behavior defaults to winsymlink=1 and in previous versions versions to winsymlink=0. With winsymlink=1 the actual behavior started to get problematic (see official documentation).

Potentially it might be also possible to drop godebug winsymlink=0 into the go.mod, but to have a debug statement in a product for release feels not right. :-)

[ldez]

Can you show me the error log you have?

This is to document the topic.

[blaubaer]

@ldez

Can you show me the error log you have?

This is to document the topic.

Sure. In this example I've mounted my Dev Drive under C:\development this means this is the Junction point. I've run golangci-lint run inside the folder C:\development\github.com\blaubaer\golangci-lint and get the following result without this PR applied:

level=warning msg="[config_reader] Can't pretty print config file path: can't get working directory: can't eval symlinks on wd C:\\development\\github.com\\blaubaer\\golangci-lint: The system cannot find the path specified."
panic: Can't get working dir: can't eval symlinks on wd C:\development\github.com\blaubaer\golangci-lint: The system cannot find the path specified.

goroutine 1 [running]:
github.com/golangci/golangci-lint/pkg/result/processors.NewPathShortener()
	C:/development/github.com/blaubaer/golangci-lint/pkg/result/processors/path_shortener.go:20 +0xa9
github.com/golangci/golangci-lint/pkg/lint.NewRunner({0x1975dc0, 0xc00111db00}, 0xc00033ac08, {0x24d44e0, 0x0, 0x0}, 0xc00125ea80, 0xc00127d380, 0xc00125eaa0, 0xc00122e280, ...)
	C:/development/github.com/blaubaer/golangci-lint/pkg/lint/runner.go:93 +0xa1c
github.com/golangci/golangci-lint/pkg/commands.(*runCommand).runAnalysis(0xc001084ea0, {0x196da70, 0xc0012b3ce0}, {0x24d44e0, 0x0, 0x0})
	C:/development/github.com/blaubaer/golangci-lint/pkg/commands/run.go:385 +0x1b2
github.com/golangci/golangci-lint/pkg/commands.(*runCommand).runAndPrint(0xc001084ea0, {0x196da70, 0xc0012b3ce0}, {0x24d44e0, 0x0, 0x0})
	C:/development/github.com/blaubaer/golangci-lint/pkg/commands/run.go:348 +0x26d
github.com/golangci/golangci-lint/pkg/commands.(*runCommand).execute(0xc001084ea0, 0xc000c13a90?, {0x24d44e0, 0x0, 0x0})
	C:/development/github.com/blaubaer/golangci-lint/pkg/commands/run.go:254 +0x1f3
github.com/spf13/cobra.(*Command).execute(0xc0010aa608, {0x24d44e0, 0x0, 0x0})
	C:/Users/gregor.noczinski/go/pkg/mod/github.com/spf13/[email protected]/command.go:989 +0xa91
github.com/spf13/cobra.(*Command).ExecuteC(0xc0010aa008)
	C:/Users/gregor.noczinski/go/pkg/mod/github.com/spf13/[email protected]/command.go:1117 +0x3ff
github.com/spf13/cobra.(*Command).Execute(...)
	C:/Users/gregor.noczinski/go/pkg/mod/github.com/spf13/[email protected]/command.go:1041
github.com/golangci/golangci-lint/pkg/commands.(*rootCommand).Execute(0xc0010a3a70)
	C:/development/github.com/blaubaer/golangci-lint/pkg/commands/root.go:83 +0x3d
github.com/golangci/golangci-lint/pkg/commands.Execute({{0x1959a50, 0x8}, {0x19e444f, 0x7}, {0xc0004b0f00, 0x47}, {0x19e872f, 0x14}})
	C:/development/github.com/blaubaer/golangci-lint/pkg/commands/root.go:17 +0x5a
main.main()
	C:/development/github.com/blaubaer/golangci-lint/cmd/golangci-lint/main.go:25 +0xc5

With this PR applied:

<empty> 😉

BTW: I works also without this PR if I mount it at a dedicated drive like at drive F:. Running then inside F:\github.com\blaubaer\golangci-lint, works too, but is not desired.

[ldez]

LGTM