Re: [ptxdist] system bash replacement

[Erwin Rol <mailinglists@erwinrol.com>]

On Mon, 2017-09-11 at 10:28 +0200, Michael Olbrich wrote:
> Hi,
> 
> On Sat, Sep 09, 2017 at 10:59:34AM +0200, Erwin Rol wrote:
> > I have several (older) CentOS 6.X (and even 5.X :-/ ) systems that have
> > bash 4.1.2 which is to old for newer ptxdist releases.
> > 
> > Ptxdist checks for several tools and places links in its $PTXDIR/bin/
> > dir. Tools include cp, ls, awk, and bash. The ptxdist $PTXDIR/bin/ dir
> > is placed in PATH so those links in $PTXDIR/bin/ are found first.
> > 
> > But! all ptxdist scripts have "#!/bin/bash" in them, so that bash link
> > in $PTXDIR/bin/ is never used. 
> > 
> > I have some success by replacing "#!/bin/bash" with "#!/usr/bin/env
> > bash" but before I go ahead with that I would like to hear if someone
> > already tried that and failed (or succeeded).
> > 
> > BTW the same for the python link, scripts with #!/bin/python  will not
> > use it. 
> 
> I've never tried this, but I had some ideas:
> 
> 1. We already set SHELL=$(PTXDIST_TOPDIR)/bin/bash in
>    rules/other/Toplevel.make so that handles some of it.
> 2. PTXdist itself is a problem. I had some ideas about re-executing ptxdist
>    if the shell is different from $(PTXDIST_TOPDIR)/bin/bash.

I already have some "wrapper" around ptxdist so I have a bash there and
that is first in the path so "#!/usr/bin/env bash" works for me. But
that surely isn't a general solution for ptxdist.  

BTW I found out the awk should be version checked, cause the CentOS 6
awk silently fails, causing the dependencies to be not generated and so
building just starts with some random package. 

In the end things still didn't want to work right. So I ended up
creating a chroot where I bind mount everything from the host under
host_root. Than create a bin dir  and symlink everything from
host_root/bin/. Than replace the bash link with the new bash (and the
same with the awk). The other dirs like lib, etc, opt I just ln to the
dir in host_root. After that I can chroot in it and everything looks
like my host but with a new shell and awk. Also had to get a new host
GCC (4.4.8 is to old for the toolchain building). But in the end I was
able to build the lastest ptxdist toolchain on Centos 6 without changing
the host OS. 

It is like a mini "container", if I would selectively setup usr/lib/ and
usr/include it could also be used to prevent pulling in host stuff. 

- Erwin


_______________________________________________
ptxdist mailing list
ptxdist@pengutronix.de