Hangs when installing VS2017

[jordanbtucker]

C:\WINDOWS\system32>npm i -g --production --vs2017 install windows-build-tools

> windows-build-tools@3.1.0 postinstall C:\Users\Jordan\scoop\persist\nodejs-lts\bin\node_modules\windows-build-tools
> node ./dist/index.js

Downloading vs_BuildTools.exe
Downloading python-2.7.14.amd64.msi
[============================================>] 100.0% of 20.17 MB (8.07 MB/s)
Downloaded python-2.7.14.amd64.msi. Saved to C:\Users\Jordan\.windows-build-tools\python-2.7.14.amd64.msi.

Starting installation...
Launched installers, now waiting for them to finish.
This will likely take some time - please be patient!

Status from the installers:
---------- Visual Studio Build Tools ----------
2018-08-12T23:30:25 : Verbose : [SetupUpdaterImpl]: Rpc connection was closed.
2018-08-12T23:30:25 : Verbose : [SetupUpdaterImpl]: Stream was closed

------------------- Python --------------------
Successfully installed Python 2.7

The only info that gets output is:

2018-08-12T23:30:25 : Verbose : [SetupUpdaterImpl]: Rpc connection was closed.
2018-08-12T23:30:25 : Verbose : [SetupUpdaterImpl]: Stream was closed

No Build Tools components get installed, and it just hangs forever.

[jordanbtucker]

The RPC messages are red herrings. They're just left over messages from previous logs. If you delete the logs first, then it hangs with:

---------- Visual Studio Build Tools ----------
Still waiting for installer log file...

The actual failure is indicated in the dd_bootstrapper logs:

VisualStudio Bootstrapper:8/13/2018 2:37:30 AM: Starting vs setup process 'vs_installer.exe' with arguments '/finalizeInstall install --in "C:\ProgramData\Microsoft\VisualStudio\Packages\_bootstrapper\vs_setup_bootstrapper_201808130237109785.json" --norestart --quiet --add Microsoft.VisualStudio.Workload.VCTools --locale en-US --activityId "b3bbd12d-ae53-4412-b7f9-0a65e02a9ead"'.
VisualStudio Bootstrapper:8/13/2018 2:37:30 AM: Caught Exception: Type = ArgumentException, Message = Item has already been added. Key in dictionary: 'path'  Key being added: 'Path', StackTrace =    at System.Collections.Hashtable.Insert(Object key, Object nvalue, Boolean add)
   at System.Diagnostics.ProcessStartInfo.get_EnvironmentVariables()
   at Microsoft.VisualStudio.Setup.Bootstrapper.Bootstrapper.StartProcess(String exeDir, String exeName, String args)
VisualStudio Bootstrapper:8/13/2018 2:37:30 AM: Couldn't launch setup process. Error: Item has already been added. Key in dictionary: 'path'  Key being added: 'Path'
VisualStudio Bootstrapper:8/13/2018 2:37:30 AM: Caught Exception: Type = BootstrapperException, Message = Unable to launch the installer. Error: Item has already been added. Key in dictionary: 'path'  Key being added: 'Path', StackTrace =    at Microsoft.VisualStudio.Setup.Bootstrapper.Bootstrapper.StartProcess(String exeDir, String exeName, String args)
   at Microsoft.VisualStudio.Setup.Bootstrapper.Bootstrapper.ExecuteCore()
   at Microsoft.VisualStudio.Setup.Bootstrapper.Bootstrapper.<>c__DisplayClass20_0.<Execute>b__0(Object s)
InnerException:Type = ArgumentException, Message = Item has already been added. Key in dictionary: 'path'  Key being added: 'Path', StackTrace =    at System.Collections.Hashtable.Insert(Object key, Object nvalue, Boolean add)
   at System.Diagnostics.ProcessStartInfo.get_EnvironmentVariables()
   at Microsoft.VisualStudio.Setup.Bootstrapper.Bootstrapper.StartProcess(String exeDir, String exeName, String args)
VisualStudio Bootstrapper:8/13/2018 2:37:30 AM: Boostrapper failed. Exception: Unable to launch the installer. Error: Item has already been added. Key in dictionary: 'path'  Key being added: 'Path'

Apparently it doesn't like the fact that npm adds PATH and path aliases to the existing Path env var.

Patching launch.ts with:

delete process.env.PATH;
delete process.env.path;

right before it spawns powershell.exe seems to do the trick.

[jordanbtucker]

The npm bug that's causing this issue.

https://npm.community/t/3-path-variables-are-assigned-to-child-process-launched-by-npm/1042

[jordanbtucker]

A fix has been merged into npm-lifecycle, so it should be fixed in the next version of npm. Until then, it may be good to patch this for npm >=6.1.0 and <6.4.0.

[felixrieseberg]

@jordanbtucker Thank you so much for your excellent research! I've fixed this in 3859517.