[Feature Request]: Expand $(~) to $(HOME) or $(USERPROFILE) depending on OS

[kzu]

Summary

Currently, you need to do something like the following to consistently get the ~ home directory in a cross-platform way:

<PropertyGroup>
    <UserProfileHome Condition="'$([MSBuild]::IsOSUnixLike())' == 'true'">$(HOME)</UserProfileHome>
    <UserProfileHome Condition="'$([MSBuild]::IsOSUnixLike())' != 'true'">$(USERPROFILE)</UserProfileHome>
</PropertyGroup>

It would be awesome if the well-known shorthand ~ (even PowerShell Core knows it) could be used directly in MSBuild as a built-in envvar alias for either $(HOME) or $(USERPROFILE) depending on the current OS, just like pwsh does it.

Background and Motivation

No particular problem, just a desire for more consistency across developer tooling in the ecosystem (following the lead from pwsh).

Proposed Feature

Summary contains the proposal, which would be to consider ~ as an alias to either Home or UserProfile envvar names in Unix-like vs Windows.

Alternative Designs

No response

[danmoseley]

Or MsbuildHomeDir ?

[AR-May]

Team triage: @baronfel what do you think of this suggestion?

[baronfel]

It seems reasonable to me, but we should check for consistency with the Runtime's SpecialFolders enum in addition to various popular shells like bash, zsh, fish, and pwsh.

[kzu]

@danmoseley that would be confusing, since it might mean the MSBuild home dir (i.e. where msbuild.exe lives).