[luatex] Strange behavior for io.popen

[Dirk Laurie]

2017-06-06 22:57 GMT+02:00 David Carlisle <d.p.carlisle at gmail.com>:
>
>
> On 6 June 2017 at 20:02, Br. Samuel Springuel <rpspringuel at gmail.com> wrote:
>>
>>
>> Besides the original Ubuntu 16.04 system this was seen on, we've also been
>> able to confirm it on Gentoo, Mac 10.10 (Yosemite), and Windows 10 and so
>> believe the problem to be platform independent.
>>
>
> same in cygwin, here's a plain tex example
>
> \directlua{
>  f = io.popen('cd', 'r')
> }
> \bye
>
> which produces
>
>
> This is LuaTeX, Version 1.0.5 (TeX Live 2017)
>  system commands enabled.
> (./file.tex)
> warning  (pdf backend): no pages of output.
> Transcript written on file.log.
> /bin/sh: all: command not found

'cd' is not a program that can be started in a separated process,
it is a shell builtin command. Do you get the same with 'ls'?