Bug #95816 for App-perlbrew: perlbrew-specific bashrc breaks Linux system upgrade

Tue May 20 19:43:07 2014 jkeenan [...] cpan.org - Ticket created

Subject:

perlbrew-specific bashrc breaks Linux system upgrade

Today I upgraded a machine from Ubuntu 13.10 LTS to 14.04 LTS. There were no problems with the upgrade itself whatsoever. However, when I opened the Terminal application to resume Perl 5 development, I immediately encountered problems. 1. I got this error message *immediately* upon opening Terminal: ##### Can't locate App/perlbrew.pm in @INC (you may need to install the App::perlbrew module) (@INC contains: /etc/perl /usr/local/lib/perl/5.18.2 /usr/local/share/perl/5.18.2 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.18 /usr/share/perl/5.18 /usr/local/lib/site_perl .) at /usr/local/bin/perlbrew line 6. BEGIN failed--compilation aborted at /usr/local/bin/perlbrew line 6. Can't locate App/perlbrew.pm in @INC (you may need to install the App::perlbrew module) (@INC contains: /etc/perl /usr/local/lib/perl/5.18.2 /usr/local/share/perl/5.18.2 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.18 /usr/share/perl/5.18 /usr/local/lib/site_perl .) at /usr/local/bin/perlbrew line 6. BEGIN failed--compilation aborted at /usr/local/bin/perlbrew line 6. ##### 2. I found that most of the Unix command-line programs could no longer be located. Examples: ##### [~] 4 $ vi .bashrc Command 'vi' is available in '/usr/bin/vi' The command could not be located because '/usr/bin' is not included in the PATH environment variable. vi: command not found [~] 5 $ ls -l . Command 'ls' is available in '/bin/ls' The command could not be located because '/bin' is not included in the PATH environment variable. ls: command not found ##### Repeated inspection of ~/.bashrc showed me that when I had installed perlbrew on this machine back in March, I had had to add the following line: ##### source ~/perl5/perlbrew/etc/bashrc ##### I then inspected this perlbrew-specific bashrc. I believe that the fundamental, system-wide values for the PATH environmental variable -- established (at least in Ubuntu) in /etc/environment -- were *probably* being overwritten by code like this: ##### PATH_WITHOUT_PERLBREW=$(eval $perlbrew_command display-pristine-path) if [ -n "$PERLBREW_PATH" ]; then export PATH=${PERLBREW_PATH}:${PATH_WITHOUT_PERLBREW} else export PATH=${PERLBREW_ROOT}/bin:${PATH_WITHOUT_PERLBREW} fi unset PATH_WITHOUT_PERLBREW ##### Once I commented out that 'source' line in my ~/.bashrc file, I regained access to the PATH values from /etc/environment (as well as those I had manually entered in ~/.bashrc via, e.g., "PATH=$HOME/bin/perl:$HOME/bin/shell:$PATH"). So I now have no problem using vi, ls, etc. But the consequence is that I can no longer use 'perlbrew', since it is that perlbrew-specific bashrc file that establishes 'perlbrew' as a *shell* command. Example: ##### $ perlbrew list Can't locate App/perlbrew.pm in @INC (you may need to install the App::perlbrew module) (@INC contains: /etc/perl /usr/local/lib/perl/5.18.2 /usr/local/share/perl/5.18.2 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.18 /usr/share/perl/5.18 /usr/local/lib/site_perl .) at /usr/local/bin/perlbrew line 6. BEGIN failed--compilation aborted at /usr/local/bin/perlbrew line 6. ##### I certainly have 'perlbrew' installed; it just can't be located and for some reason throws up that error. This is a serious design flaw in perlbrew. Thank you very much. Jim Keenan

Tue May 20 19:44:05 2014 jkeenan [...] cpan.org - Severity Important added

Tue May 20 20:01:02 2014 jkeenan [...] cpan.org - Correspondence added

On Tue May 20 19:43:07 2014, JKEENAN wrote: [snip] Show quoted text

> > I then inspected this perlbrew-specific bashrc. I believe that the > fundamental, system-wide values for the PATH environmental variable -- > established (at least in Ubuntu) in /etc/environment -- were > *probably* being overwritten by code like this: > > ##### > PATH_WITHOUT_PERLBREW=$(eval $perlbrew_command display-pristine-path) > if [ -n "$PERLBREW_PATH" ]; then > export PATH=${PERLBREW_PATH}:${PATH_WITHOUT_PERLBREW} > else > export PATH=${PERLBREW_ROOT}/bin:${PATH_WITHOUT_PERLBREW} > fi > unset PATH_WITHOUT_PERLBREW > ##### >

Indeed, when I inserted the following line immediately below the assignment to PATH_WITHOUT_PERLBREW, it became clear that PATH_WITHOUT_PERLBREW was being assigned an empty string: ##### echo "xxx: $PATH_WITHOUT_PERLBREW" ##### This is consistent with the disappearance of the system-wide values in the PATH string originating in /etc/environment. 'man perlbrew' continues to work, but 'perlbrew' as a shell command no longer does. Thank you very much. Jim Keenan PATH_WITHOUT_PERLBREW=$(eval $perlbrew_command display-pristine-path)

Tue May 20 20:11:59 2014 jkeenan [...] cpan.org - Correspondence added

On Tue May 20 20:01:02 2014, JKEENAN wrote: Show quoted text

> On Tue May 20 19:43:07 2014, JKEENAN wrote: > > [snip]

> > > > I then inspected this perlbrew-specific bashrc. I believe that the > > fundamental, system-wide values for the PATH environmental variable > > -- > > established (at least in Ubuntu) in /etc/environment -- were > > *probably* being overwritten by code like this: > > > > ##### > > PATH_WITHOUT_PERLBREW=$(eval $perlbrew_command display-pristine-path) > > if [ -n "$PERLBREW_PATH" ]; then > > export PATH=${PERLBREW_PATH}:${PATH_WITHOUT_PERLBREW} > > else > > export PATH=${PERLBREW_ROOT}/bin:${PATH_WITHOUT_PERLBREW} > > fi > > unset PATH_WITHOUT_PERLBREW > > ##### > >

> > Indeed, when I inserted the following line immediately below the > assignment to PATH_WITHOUT_PERLBREW, it became clear that > PATH_WITHOUT_PERLBREW was being assigned an empty string: > > ##### > echo "xxx: $PATH_WITHOUT_PERLBREW" > ##### > > This is consistent with the disappearance of the system-wide values in > the PATH string originating in /etc/environment. > > 'man perlbrew' continues to work, but 'perlbrew' as a shell command no > longer does. >

Further data: When I *once again* called: ##### cpanm App::perlbrew ##### ... without un-commenting the '#source ~/perl5/perlbrew/etc/bashrc' line in my ~/.bashrc, then it appeared that the 'perlbrew' command once again became available: ##### $ perlbrew list perl-5.6.2 perl-5.16.3 perl-5.18.2 ##### However, it will take further investigation to see how this can be happening *without* source-ing the perlbrew-specific bashrc file into ~/.bashrc. Thank you very much. Jim Keenan

Tue May 20 20:15:20 2014 jkeenan [...] cpan.org - Correspondence added

On Tue May 20 20:11:59 2014, JKEENAN wrote: Show quoted text

> On Tue May 20 20:01:02 2014, JKEENAN wrote:

> > On Tue May 20 19:43:07 2014, JKEENAN wrote: > > > > [snip]

> > > > > > I then inspected this perlbrew-specific bashrc. I believe that the > > > fundamental, system-wide values for the PATH environmental variable > > > -- > > > established (at least in Ubuntu) in /etc/environment -- were > > > *probably* being overwritten by code like this: > > > > > > ##### > > > PATH_WITHOUT_PERLBREW=$(eval $perlbrew_command display-pristine- > > > path) > > > if [ -n "$PERLBREW_PATH" ]; then > > > export PATH=${PERLBREW_PATH}:${PATH_WITHOUT_PERLBREW} > > > else > > > export PATH=${PERLBREW_ROOT}/bin:${PATH_WITHOUT_PERLBREW} > > > fi > > > unset PATH_WITHOUT_PERLBREW > > > ##### > > >

> > > > Indeed, when I inserted the following line immediately below the > > assignment to PATH_WITHOUT_PERLBREW, it became clear that > > PATH_WITHOUT_PERLBREW was being assigned an empty string: > > > > ##### > > echo "xxx: $PATH_WITHOUT_PERLBREW" > > ##### > > > > This is consistent with the disappearance of the system-wide values > > in > > the PATH string originating in /etc/environment. > > > > 'man perlbrew' continues to work, but 'perlbrew' as a shell command > > no > > longer does. > >

> > Further data: > > When I *once again* called: > > ##### > cpanm App::perlbrew > ##### > > ... without un-commenting the '#source ~/perl5/perlbrew/etc/bashrc' > line in my ~/.bashrc, then it appeared that the 'perlbrew' command > once again became available: > > ##### > $ perlbrew list > perl-5.6.2 > perl-5.16.3 > perl-5.18.2 > ##### > > However, it will take further investigation to see how this can be > happening *without* source-ing the perlbrew-specific bashrc file into > ~/.bashrc. >

Things are not quite right. On the basis of previous use, I would expect 'perlbrew switch' or 'perlbrew use' to change the active perl *in the current shell*. Instead, these commands are *opening sub-shells*: ##### $ perlbrew switch perl-5.16.3 A sub-shell is launched with perl-5.16.3 as the activated perl. Run 'exit' to finish it. bash-4.3$ exit exit $ perlbrew use perl-5.16.3 A sub-shell is launched with perl-5.16.3 as the activated perl. Run 'exit' to finish it. bash-4.3$ exit exit Show quoted text

> Thank you very much. > Jim Keenan

Wed May 21 00:34:54 2014 KENTNL [...] cpan.org - Correspondence added

>
> #####
> $ perlbrew switch perl-5.16.3
>
> A sub-shell is launched with perl-5.16.3 as the activated perl. Run
> 'exit' to finish it.
>
> bash-4.3$ exit
> exit
>
> $ perlbrew use perl-5.16.3
>
> A sub-shell is launched with perl-5.16.3 as the activated perl. Run
> 'exit' to finish it.
>
> bash-4.3$ exit
> exit
>
> > Thank you very much.
> > Jim Keenan

The causes of those 2 problems usually indicates that for whatever reason, the perlbrew helper is not in your current bash session.

ie: after you "fix" whatever was previously wrong with perlbrew, you will need to possibly subsequently spawn a new shell that consumes the relevant bashrc to ensure the bash hook that makes this behaviour work is in place.

Wed May 21 00:34:54 2014 The RT System itself - Status changed from 'new' to 'open'

Wed May 21 00:47:35 2014 KENTNL [...] cpan.org - Cc KENTNL added

Wed May 21 08:34:36 2014 jkeenan [...] cpan.org - Correspondence added

On Tue May 20 20:15:20 2014, JKEENAN wrote: Show quoted text

> On Tue May 20 20:11:59 2014, JKEENAN wrote:

> > On Tue May 20 20:01:02 2014, JKEENAN wrote:

> > > On Tue May 20 19:43:07 2014, JKEENAN wrote: > > > > > > [snip]

> > > > > > > > I then inspected this perlbrew-specific bashrc. I believe that > > > > the > > > > fundamental, system-wide values for the PATH environmental > > > > variable > > > > -- > > > > established (at least in Ubuntu) in /etc/environment -- were > > > > *probably* being overwritten by code like this: > > > > > > > > ##### > > > > PATH_WITHOUT_PERLBREW=$(eval $perlbrew_command display-pristine- > > > > path) > > > > if [ -n "$PERLBREW_PATH" ]; then > > > > export PATH=${PERLBREW_PATH}:${PATH_WITHOUT_PERLBREW} > > > > else > > > > export PATH=${PERLBREW_ROOT}/bin:${PATH_WITHOUT_PERLBREW} > > > > fi > > > > unset PATH_WITHOUT_PERLBREW > > > > ##### > > > >

> > > > > > Indeed, when I inserted the following line immediately below the > > > assignment to PATH_WITHOUT_PERLBREW, it became clear that > > > PATH_WITHOUT_PERLBREW was being assigned an empty string: > > > > > > ##### > > > echo "xxx: $PATH_WITHOUT_PERLBREW" > > > ##### > > > > > > This is consistent with the disappearance of the system-wide values > > > in > > > the PATH string originating in /etc/environment. > > > > > > 'man perlbrew' continues to work, but 'perlbrew' as a shell command > > > no > > > longer does. > > >

> > > > Further data: > > > > When I *once again* called: > > > > ##### > > cpanm App::perlbrew > > ##### > > > > ... without un-commenting the '#source ~/perl5/perlbrew/etc/bashrc' > > line in my ~/.bashrc, then it appeared that the 'perlbrew' command > > once again became available: > > > > ##### > > $ perlbrew list > > perl-5.6.2 > > perl-5.16.3 > > perl-5.18.2 > > ##### > > > > However, it will take further investigation to see how this can be > > happening *without* source-ing the perlbrew-specific bashrc file into > > ~/.bashrc. > >

> > Things are not quite right. On the basis of previous use, I would > expect 'perlbrew switch' or 'perlbrew use' to change the active perl > *in the current shell*. Instead, these commands are *opening sub- > shells*: > > ##### > $ perlbrew switch perl-5.16.3 > > A sub-shell is launched with perl-5.16.3 as the activated perl. Run > 'exit' to finish it. > > bash-4.3$ exit > exit > > $ perlbrew use perl-5.16.3 > > A sub-shell is launched with perl-5.16.3 as the activated perl. Run > 'exit' to finish it. > > bash-4.3$ exit > exit >

In addition to help from KENTNL above, I also received help from David Golden on the cpan-workers mailing list. It appears that when I was trying to fix the problem yesterday, I was saying "cpanm App::perlbrew", which was failing to place the "fatpacked" version of 'perlbrew' into ~/perl5/perlbrew/bin. (The only thing I had in that directory was 'patchperl'.) Once I did the following: 1. curl -kL http://install.perlbrew.pl | bash 2. Uncomment 'source ~/perl5/perlbrew/etc/bashrc' in ~/.bashrc 3. 'source ~/.bashrc' Then 'perlbrew' returned to its expected behavior, i.e., 'perlbrew use perl-5.16.3' caused 5.16.3 to be activated in the same shell; no sub-shell was opened. The documentation for App::perlbrew should be modified so that people know how to work around this problem in the future. Thank you very much. Jim Keenan