bash usage of fdescfs [was: Re: amd64/188699: Dev tree]

[John Baldwin]

On Monday, April 21, 2014 3:51:33 pm Konstantin Belousov wrote:
> On Mon, Apr 21, 2014 at 02:31:12PM -0400, John Baldwin wrote:
> > On Thursday, April 17, 2014 2:50:01 pm Konstantin Belousov wrote:
> > > The following reply was made to PR amd64/188699; it has been noted by 
GNATS.
> > > 
> > > From: Konstantin Belousov <kostikbel at gmail.com>
> > > To: John Allman <freebsd at hugme.org>
> > > Cc: freebsd-gnats-submit at FreeBSD.org
> > > Subject: Re: amd64/188699: Dev tree
> > > Date: Thu, 17 Apr 2014 21:44:52 +0300
> > > 
> > >  On Wed, Apr 16, 2014 at 05:32:45PM +0000, John Allman wrote:
> > >  > This is how to reproduce it:
> > >  > 
> > >  > Fresh install of 10 on AMD 64
> > >  > install bash `pkg install bash`
> > >  > Switch to bash `bash`
> > >  > push a here document into a loop: `while true ; do echo; done< <(echo 
"123")`
> > >  > receive an error: "-su: /dev/fd/62: No such file or directory"
> > >  > 
> > >  > I'm sorry I haven't been able to research this any further. I found 
how while working on some important matters. As I mentioned the above works 
fine in all 
> > previous versions of FreeBSD up until 10.
> > >  > >How-To-Repeat:
> > >  > Fresh install
> > >  > pkg install bash
> > >  > bash
> > >  > while true; do echo foo done< <(echo "123")
> > >  > 
> > >  > -su: /dev/fd/62: No such file or directory
> > >  
> > >  So do you have fdescfs mounted on /dev/fd on the machine where the
> > >  test fails ?  It works for me on head, and if unmounted, I get the
> > >  same failure message as yours.  I very much doubt that it has anything
> > >  to do with a system version.
> > 
> > Question I have is why is bash deciding to use /dev/fd/<n> and require
> > fdescfs?  On older releases bash uses named pipes for this instead.
> 
> The aclocal.m4 contains the test which verifies the presence and usability
> of /dev/fd/n for n>=3 on the _build_ host.  The result of the test
> is used on the installation host afterward.
> 
> Such kinds of bugs are endemic in our ports, but apparently upstreams
> are guilty too.

Yuck, yuck.  Should we fix our default package builders to not mount fdescfs?

-- 
John Baldwin