Bug 208391
| Summary: | misc/mc SUBSHELL not working with /bin/sh | ||||||
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| Product: | Ports & Packages | Reporter: | gja822 | ||||
| Component: | Individual Port(s) | Assignee: | Alexey Dokuchaev <danfe> | ||||
| Status: | Closed FIXED | ||||||
| Severity: | Affects Some People | CC: | 0mp, danfe, doctorwhoguy, woodsb02 | ||||
| Priority: | --- | ||||||
| Version: | Latest | ||||||
| Hardware: | Any | ||||||
| OS: | Any | ||||||
| URL: | https://www.midnight-commander.org/ticket/3658 | ||||||
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Description
gja822
2016-03-30 04:15:18 UTC
I have reported this problem to the upstream mc project team here: https://www.midnight-commander.org/ticket/3658 This is a longstanding bug. I would suggest that the subshell build option be disabled by default or that, at the very least, an informational message be emitted that a user either needs to use the -u option to start or that the user's default shell should be changed, if a different shell will cause it to work. It looks like the ticket is still pending: https://midnight-commander.org/ticket/373 Interestingly, Debian ash and BusyBox ash are now supported: https://github.com/MidnightCommander/mc/commit/f596c916a42a0868897b3314e557b0a82df37017 Created attachment 218560 [details]
Add pkg-message explaining the issue
Would you mind if I commit the attached pkg-message to explain the problem to our users?
Sorry, due to a lack of time I have reset the maintainer of this port back to ports@FreeBSD.org. Hopefully someone else is able to step in to help. Resetting the assignee of this bug accordingly. (In reply to Patrick McMunn from comment #2) > This is a longstanding bug. Well, it depends on one's definition of a bug. :-) Technically, ``env SHELL=/bin/sh mc'' tells users up-front that this combination is unsupported and refuses to work. It could probably emit less cryptic diagnostics, but that's about it. It's simply not possible to support /bin/sh as a subshell in a way mc(1) deals with shells. When it launches a subshell, mc(1) installs so called "precmd" hook (executed before each prompt) so the shell can report its current working directory back to mc(1). Some shells are advanced enough and provide this feature out of the box, e.g. for bash(1): > echo $PROMPT_COMMAND > pwd>&7;kill -STOP $$ For tcsh(1): > alias > ... > precmd echo $cwd:q >>/tmp/mc-danfe/mc.pipe.78491; kill -STOP $$ Other supported shells like dash(1) are not so advanced, but they support command expansion in the PS1, so this behavior can be emulated. Alas, our /bin/sh supports none of these. > I would suggest that the subshell build option be disabled by default We should not cripple package defaults just for the sake of ~1% of users who are confined to /bin/sh as their interactive shell. > or that, at the very least, an informational message be emitted that a user > either needs to use the -u option to start or that the user's default shell > should be changed Yes, that's what we should do. I'll take Mateusz's text but rework it, as it's a bit too wordy while lacking technical details about this issue. (In reply to Alexey Dokuchaev from comment #6) Thanks for working on that! A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/ports/commit/?id=b20b92686b504c322dd809c3107acb4edda0eb08 commit b20b92686b504c322dd809c3107acb4edda0eb08 Author: Alexey Dokuchaev <danfe@FreeBSD.org> AuthorDate: 2021-05-27 08:42:00 +0000 Commit: Alexey Dokuchaev <danfe@FreeBSD.org> CommitDate: 2021-05-27 08:42:43 +0000 misc/mc: the port had been improved (+) - GC outdated CONFLICTS (misc/mc-light had been removed on 2019-10-16) - Add missing SCREEN_DESC (screen library) option description - Offer new option, EXTATTR (ext2fs extended attributes support) and ensure, in somewhat ugly way, that dependency on `sysutils/e2fsprogs' won't be silently picked up if this option is disabled - Tell users that /bin/sh, our base system sh(1), is not supported as concurrent subshell because it does not allow "precmd" hooks [1] - Fix entering RAR archives after `archivers/unrar` had been updated to version 6.x [2] - Use helper target and simplify installation of documentation files PR: 208391 [1], 251404 [2] misc/mc/Makefile | 36 +++++++++++++++++++----------------- misc/mc/files/pkg-message.in (new) | 17 +++++++++++++++++ 2 files changed, 36 insertions(+), 17 deletions(-) |
