add warning to postinstall

[knowbody]

FormidableLabs/victory#98 (comment)

[coopy]

@knowbody I needed to add ( ... ) around the echo && exit 1 condition, otherwise exit 1 always happens.

The weird c++ error is a separate issue that has been around for a while (try expanding the $ npm install part of the output in https://travis-ci.org/FormidableLabs/victory-axis/jobs/98165885, for example).

[coopy]

I created https://github.com/FormidableLabs/victory-axis/issues/71

[boygirl]

yay! thanks @coopy

[ryan-roemer]

@knowbody @coopy -- Has anyone validated this on Windows? (with the new parens)

[knowbody]

@ryan-roemer I didn't, no windows machine. Would be great to add appveyor ASAP

[ryan-roemer]

@knowbody -- I see ievms and iectrl in your future ;)

[knowbody]

@ryan-roemer the last windows I saw, was win98 😜

but let me see the "future"

[ryan-roemer]

@knowbody -- Here, I did it for you ;)

Here is a "failing" command with parens:

> cmd /C "cd lib || (echo hi && exit 1)"
The system cannot find the path specified.
hi

> echo %errorlevel%
1

Here is a success command:

> cmd /C "echo ho || (echo hi && exit 1)"
ho

> echo %errorlevel%
0

So it appears everything works on windows with the parens as we have it now.

[knowbody]

Thank you @ryan-roemer, I'm checking ievms and iectrl anyway!

[coopy]

👍