build-system/exec.js : getOutput returns invalid object

[Galphimbl]

What's the issue?

build-system/exec.js : getOutput returns object with stdout === null && stderr === null

node -v
v8.9.4

yarn -v
1.3.2

gulp -v
[11:31:54] CLI version 3.9.1

How do we reproduce the issue?

1. clone https://github.com/Galphimbl/amphtml
2. run "yarn install" or "gulp"

[aghassemi]

/to @rsimha-amp for triage

[rsimha]

@Galphimbl Can you talk about where you are using getOutput? Is this being run as part of build-system/check-package-manager.js (which is run before yarn), or are you calling it somewhere else?

The recommended version of node for AMP development is v6. Could you try running nvm install 6 followed by yarn to see if the issue still repros?

[rsimha]

I just switched to your versions and am not seeing the error. What OS are you running on? How are you calling the command? (getOutput pipes the stdout and stderr to the calling process)

[Galphimbl]

@rsimha-amp My OS is windows 10.
Version: 1703
OS Build: 15063.850
System type: 64-bit operation system, x64-based processor

same issue on node v6.12.3
getOutput run as part of build-system/check-package-manager.js.

i can comment preinstall script and install all dependencies, but gulp also use this in build-system\tasks\update-packages.js:30:30

[rsimha]

@Galphimbl Looks like we were starting a posix-only shell. #13156 should fix this.

[rsimha]

@Galphimbl let me know if the fix works on windows.