PATH contains dot when PATH is unset before running bash

The problem seems to have been introduced in 14.04

philippe@pv-desktop:~$ for i in 12.04 12.10 13.04 13.10 14.04 14.10 15.04 15.10 16.04; do echo $i; docker run -it --rm ubuntu:$i bash -c "unset PATH; /bin/bash -c 'echo \$PATH'"; done
12.04
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
12.10
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
13.04
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
13.10
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
14.04
/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:.
14.10
/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:.
15.04
/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:.
15.10
/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:.
16.04
/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:.

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1614080/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

For information this bug does not happen on Fedora/CentOS

philippe@pv-desktop:~$ docker run -it --rm fedora:latest bash -c "unset PATH; /bin/bash -c 'echo \$PATH'"
/usr/local/bin:/usr/bin

Ah, found the same bug in Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=781367

@philippe-vaucher
I'm not quite concerned about what other distros do. Imho, it is buggy to not have `sbin` in the default built-in bash path - so i'd call fedora's bash built-in path still buggy ;-)

This bug was fixed in the package bash - 4.4.18-2ubuntu3

---------------
bash (4.4.18-2ubuntu3) cosmic; urgency=medium

  * Resurrect "Set the default path to comply with Debian policy" in
    deb-bash-config.diff which went missing since 4.2+dfsg-1 or so.
    LP: #1792004 LP: #1614080 Closes: #781367
  * Add autopkgtest for the built-in path.

 -- Dimitri John Ledkov <email address hidden> Wed, 12 Sep 2018 15:22:11 +0100

This bug was fixed in the package bash - 5.0-3ubuntu2

---------------
bash (5.0-3ubuntu2) eoan; urgency=medium

  * Resurrect "Set the default path to comply with Debian policy" in
    deb-bash-config.diff which went missing since 4.2+dfsg-1 or so.
    LP: #1792004 LP: #1614080 Closes: #781367
  * Add autopkgtest for the built-in path.

 -- Dimitri John Ledkov <email address hidden> Fri, 03 May 2019 14:31:24 +0100

Hello Philippe, or anyone else affected,

Accepted bash into disco-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/bash/5.0-3ubuntu1.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-disco to verification-done-disco. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-disco. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

Trusty is closed for SRUs, here is the diff that may be suitable for ESM.

Hello Philippe, or anyone else affected,

Accepted bash into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/bash/4.4.18-2ubuntu1.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

Hello Philippe, or anyone else affected,

Accepted bash into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/bash/4.3-14ubuntu1.3 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-xenial to verification-done-xenial. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-xenial. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

(disco-amd64)root@ottawa:~# env -u PATH /bin/bash -c 'echo $PATH'
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
(disco-amd64)root@ottawa:~# dpkg-query -W bash
bash 5.0-3ubuntu1.1

Disco looks good.

(bionic-amd64)root@ottawa:~# env -u PATH /bin/bash -c 'echo $PATH'
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
(bionic-amd64)root@ottawa:~# dpkg-query -W bash
bash 4.4.18-2ubuntu1.1

Bionic looks good.

(xenial-amd64)root@ottawa:~# env -u PATH /bin/bash -c 'echo $PATH'
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
(xenial-amd64)root@ottawa:~# dpkg-query -W bash
bash 4.3-14ubuntu1.3

Xenial looks good.

This bug was fixed in the package bash - 5.0-3ubuntu1.1

---------------
bash (5.0-3ubuntu1.1) disco; urgency=medium

  * Resurrect "Set the default path to comply with Debian policy" in
    deb-bash-config.diff which went missing since 4.2+dfsg-1 or so.
    LP: #1792004 LP: #1614080 Closes: #781367
  * Add autopkgtest for the built-in path.

 -- Dimitri John Ledkov <email address hidden> Fri, 03 May 2019 14:31:24 +0100

The verification of the Stable Release Update for bash has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

This bug was fixed in the package bash - 4.4.18-2ubuntu1.1

---------------
bash (4.4.18-2ubuntu1.1) bionic; urgency=medium

  * Resurrect "Set the default path to comply with Debian policy" in
    deb-bash-config.diff which went missing since 4.2+dfsg-1 or so.
    LP: #1792004 LP: #1614080 Closes: #781367
  * Add autopkgtest for the built-in path.

 -- Dimitri John Ledkov <email address hidden> Fri, 03 May 2019 14:50:32 +0100

This bug was fixed in the package bash - 4.3-14ubuntu1.3

---------------
bash (4.3-14ubuntu1.3) xenial; urgency=medium

  * Resurrect "Set the default path to comply with Debian policy" in
    deb-bash-config.diff which went missing since 4.2+dfsg-1 or so.
    LP: #1792004 LP: #1614080 Closes: #781367
  * Add autopkgtest for the built-in path.

 -- Dimitri John Ledkov <email address hidden> Fri, 03 May 2019 14:57:15 +0100