Paket crashes when HOME is not set

[matthid]

Description

This seems to happen in Azure DevOps Pipelines when running as root:

isaacabraham/vsts-fsharp#33

Repro steps

• Unset HOME on linux
• Run the netcore version of paket (I think the full framework one might not have this problem)

Expected behavior

Paket works

Actual behavior

Paket crashes

Known workarounds

Set HOME

[forki]

O_o ideas?

[matthid]

The problem is

Paket/src/Paket.Core/Common/Utils.fs

Line 235 in 91e3ddd

let ProgramFiles = Environment.GetFolderPath Environment.SpecialFolder.ProgramFiles

Which will crash here:

Paket/src/Paket.Core/Common/Constants.fs

Lines 48 to 73 in 91e3ddd

	let GetFolderPath sf =
	let envVar, monoPathSuffix =
	match sf with
	| ApplicationData -> "APPDATA", ".config"
	| UserProfile -> "USERPROFILE", ""
	| LocalApplicationData -> "LocalAppData", ".local/share"
	| ProgramFiles -> "PROGRAMFILES", ".programfiles"
	| ProgramFilesX86 -> "PROGRAMFILES(X86)", ".programfilesX86"
	let isWindows =
	System.Runtime.InteropServices.RuntimeInformation.IsOSPlatform(
	System.Runtime.InteropServices.OSPlatform.Windows)
	let homePath =
	if isWindows then
	let defaultPath = Environment.GetEnvironmentVariable("USERPROFILE")
	if System.String.IsNullOrEmpty defaultPath then
	Environment.GetEnvironmentVariable("HOME")
	else defaultPath
	else Environment.GetEnvironmentVariable("HOME")
	if isWindows then
	let res = Environment.GetEnvironmentVariable(envVar)
	if System.String.IsNullOrEmpty res then
	System.IO.Path.Combine(homePath, monoPathSuffix)
	else res
	else
	System.IO.Path.Combine(homePath, monoPathSuffix)

If we cannot come up with something better we could at least check homePath for null and throw a better exception (something along the lines of please set HOME environment variable). To be honest, I don't have any other idea on how to find a good path (ie the real fix).

[matthid]

Generally, exceptions in static initialization are always very unexpected (and generally badly reported) but that is something for another day.