Public bug reported:
The following code works in bash on any number of Linux distros, including
CentOS 6.10 - 7.8 and Ubuntu 14.04 - 18.04.
#!/bin/bash
#
# Test for continue from subshell issue...
#
echo SHELL is $SHELL
for i in $(seq 5)
do
(
echo loop $i
if [[ $i == 2 ]] ; then
echo i = $i - continue
continue
fi
if [[ $i == 4 ]] ; then
echo i = $i - exit
exit 1
fi
echo Loop $i subshell end
)
rc=$?
echo Loop $i rc $rc
done
--
The output on all of those machines is:
SHELL is /bin/bash
loop 1
Loop 1 subshell end
Loop 1 rc 0
loop 2
i = 2 - continue
Loop 2 rc 0
loop 3
Loop 3 subshell end
Loop 3 rc 0
loop 4
i = 4 - exit
Loop 4 rc 1
loop 5
Loop 5 subshell end
Loop 5 rc 0
---
On a Ubuntu 20.04 machine:
SHELL is /bin/bash
loop 1
Loop 1 subshell end
Loop 1 rc 0
loop 2
i = 2 - continue
packages/tmp/looptest: line 14: continue: only meaningful in a `for', `while',
or `until' loop
Loop 2 subshell end
Loop 2 rc 0
loop 3
Loop 3 subshell end
Loop 3 rc 0
loop 4
i = 4 - exit
Loop 4 rc 1
loop 5
Loop 5 subshell end
Loop 5 rc 0
--
If I change the shebang to: #!/bin/sh
the behavior is the same as the first example - except - on our machines, we
specifically link /bin/sh to bash:
$ ls -l /bin/sh
lrwxrwxrwx 1 root root 9 May 12 22:04 /bin/sh -> /bin/bash
Which seems just... weird.
This behavior seems to have started after a recent update to Ubuntu
20.04.
I realize that the argument can be made the new behavior is more technically
correct, but using a subshell to isolate vars between loops can be very helpful
and the fact that this has worked until now is concerning.
** Affects: ubuntu-docs (Ubuntu)
Importance: Undecided
Status: New
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1975866
Title:
A continue or break from a subshell inside a loop no longer works.
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/ubuntu-docs/+bug/1975866/+subscriptions
--
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
