Cannot use mercurial

[termux]

Cannot use mercurial

[fornwall]

The root cause is that the python2 package is compiled without os.link support, since hard links are not supported on Android (starting in Android version 6). This causes the line oslink = os.link to fail with the above exception.

• Adding back os.link (as a method which would would not work on Android 6) would unfortunately cause pip to break, see termux/termux-packages#29.
• If mercurial was changed to work without os.link (at least on Android) that would be great, but probably not very likely to be accepted by the mercurial project.

Does changing the line oslink = os.link to something like oslink = os.symlink in $PREFIX/lib/python2.7/site-packages/mercurial/posix.py cause mercurial to run (with basic functionality such as cloning and pushing working)?

[yajo]

I think symlinks are more error-prone than just copying (that's what AFAIK mercurial does in Windows), so I added:

[...]
import shutil
[...]
oslink = shutil.copy2
[...]

And it works like a charm!

[yajo]

Reported upstream: https://bz.mercurial-scm.org/show_bug.cgi?id=4974

[yajo]

If you could package this, you could add a patch, but maybe I'm asking for too much work...

[fornwall]

Great work reporting it to mercurial! I'll look into how much work it would be to package mercurial with this patch (otherwise I'll add a note about the manual patching steps needed when installing from pip in an upcoming collection of help pages)!

[fornwall]

A reference for the removed hard link support in Android 6 is https://code.google.com/p/android-developer-preview/issues/detail?id=3150

[durin42]

Please DO NOT package mercurial with symlinks replacing hardlinks. Copies are fine, that's what we'll fall back to anyway.

FWIW, I've mailed a fix for this to our list, and it should get reviewed in the next few days, at which point I'd really appreciate someone testing it (I'm not sure how to test it myself.)

[fornwall]

@durin42 Yes, let's forget I ever mentioned symlinks as fallbacks :).

Great, let us know here if you want us to help testing a patch (and perhaps write down instructions/steps for anything special to be tested)!

If you want to test anything yourself, install the Termux app, and then install required packages by executing

apt install python2-dev gcc

You should now be able to install mercurial with

pip2 install mercurial

[durin42]

Alrighty, if someone could test http://selenic.com/hg (if a zip is easier: https://selenic.com/hg/archive/42aa0e570eaa.zip) and let me know if it works, I'd greatly appreciate it.

Thanks!

[fornwall]

@durin42 Nice work! I built mercurial with make local and verified that basic cloning, pushing, committing, pulling and pushing works.

Do you have an estimate for which version this would be available in mercurial (and when)?

[durin42]

The patch is on our default branch for our next major release, which will be on February 1, 2016. The patch should apply to the stable branch, so if you want you can point people at a custom zip that has that applied for now.

(https://www.mercurial-scm.org/wiki/TimeBasedReleasePlan if you're curious)

On Dec 11, 2015, at 18:48, Fredrik Fornwall [email protected] wrote:

@durin42 https://github.com/durin42 Nice work! I built mercurial with make local and verified that basic cloning, pushing, committing, pulling and pushing works.

Do you have an estimate for which version this would be available in mercurial (and when)?

—
Reply to this email directly or view it on GitHub #22 (comment).

[fornwall]

Ok, interested people can apply https://selenic.com/repo/hg/rev/b0d90fef16b6 to $PREFIX/python2.7/site-packages/mercurial/posix.py after installing mercurial through pip in the meantime.

Thanks for the help!

[yajo]

Works perfectly. Anybody interested can run pip2 install https://selenic.com/hg/archive/42aa0e570eaa.zip (add --upgrade if you had a previous version).

[fornwall]

@yajo That's great! Didn't know that you could point pip to the zip file directly.