Tool installation with relative --tool-path option fails to install.

[peterhuene]

Steps to reproduce

1. dotnet install tool --tool-path foo dotnetsay

Expected behavior

Expected the tool to install into $(pwd)/foo.

Actual behavior

The installation fails:

$ dotnet install tool --tool-path foo dotnetsay
Failed to install tool package 'dotnetsay': Could not find a part of the path '/Users/peterhuene/src/cli/test/dotnet.Tests/foo/.store/.stage/5xnuzw3m.n3c/dotnetsay'.
Tool 'dotnetsay' failed to install.

Environment data

$ dotnet --info
.NET Core SDK (reflecting any global.json):
 Version:   2.1.300-preview2-008366
 Commit:    680e72993b

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  10.13
 OS Platform: Darwin
 RID:         osx.10.13-x64
 Base Path:   /Users/peterhuene/src/cli/bin/2/osx-x64/dotnet/sdk/2.1.300-preview2-008366/

Host (useful for support):
  Version: 2.1.0-preview2-26313-01
  Commit:  3c802455b2

.NET Core SDKs installed:
  2.1.300-preview2-008366 [/Users/peterhuene/src/cli/bin/2/osx-x64/dotnet/sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.All 2.1.0-preview2-30338 [/Users/peterhuene/src/cli/bin/2/osx-x64/dotnet/shared/Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.0-preview2-30338 [/Users/peterhuene/src/cli/bin/2/osx-x64/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.0-preview2-26313-01 [/Users/peterhuene/src/cli/bin/2/osx-x64/dotnet/shared/Microsoft.NETCore.App]

To install additional .NET Core runtimes or SDKs:
  https://aka.ms/dotnet-download

Bug

The tool package store is storing a relative path instead of a full path, causing a relative path to be passed to NuGet via the temp project. Thus NuGet restores relative to the temp project directory and not the current working directory.

[peterhuene]

I have a fix for this already.