It was moved to avoid a race, but that's now avoided in another way.
I prefer having it here, because this way if it somehow fails and
deletes the locpath that is going to be used, at least it will get
re-created.
Use a different tmp directory so the cache cleanup won't delete the
locpath directory while it's being populated.
This does change the hash used for the locpath directory, but it already
changed in f0ec725234
This fixes a race between two runshells from two different
bundles. One could have run the cache cleanup code, seen the
LOCPATH the other one was in the process of populating, which didn't
have a base or a buildid file written yet, and so the cache cleanup code
would delete it out from under the other process.
Also, doing it fully atomically simplifies where the races between two
runshell processes from the same bundle. Now that needs to be
dealt with to only the mv that puts it in place.
Note that, if the same bundle has 2 runshells run first thing, they will
both generate locales, which is unncessary work, but that should be a
very unusual circumstance and after the LOCPATH is set up, it won't
happen again anyway.
This should fix doc/bugs/standalone_runshell_can_race_and_fail_to_remove___96____126____47__.cache__47__git-annex__47__locales__47____96___dirs
where 2 runshells were running and the second one tried to clean up
LOCPATH while the first one was still populating it.
By moving the cleanup until after LOCPATH is populated, we guarantee
it's populated, so don't need to worry about such a race with another
process populating our same LOCPATH.
This avoids the possibility that the bundle could be updated in place,
leading to LOCPATH existing but containing locales for the old version,
which needed to be tested for with code that was not race-free.
LOCPATH/buildid is still written and checked when cleaning up stale caches.
That is not actually necessary, except old versions of the standalone
bundle expect to see it, and this prevents them cleaning up the locale
cache of a new version. And still checking it prevents the new version
cleaning up the locale cache of the old version while the old version is
still in use.
Added explicit tests before creating LOCPATH and the base and buildid files.
The buildid file no longer needs to be updated every time, because it's
stable for the given LOCPATH directory.
And the base file actually did not need to be updated every time,
because the LOCPATH is derived from base, so if the bundle is moved
elsewhere, a different LOCPATH will be used.
Transitioning to this will mean that two git-annex builds that otherwise
have the same buildid -- the same git-annex md5sum -- will use different
LOCPATH values, but that's handled fine by the cache cleanup code, so at
most it will mean one extra generation of the locale files.
This seems to be the best way to deal with the race; if the first and
second runshell are running very close together, the first will generate
the locale directory, and a second test -d would still leave a race
window.
This includes making Build.Standalone run LinuxMkLibs or OSXMkLibs
rather than doing that separately. Which is groundwork for a later
optimisation.
Also it simplified the code some.
md5sum is part of busybox, so is probably available unless it were compiled
out. If md5sum (or cut for that matter) is not available, it will
still use the whole path to $base, otherwise hash it.
Of course it's possible for md5sum to be available sometimes and not others
on the same system; in such an event the locales would be built twice for
the same bundle. The cleanup code will delete both sets once that
version of the bundle is upgraded.
A warning message is unsatisfying. But erroring out is too hard a failure,
especially since it may well work fine if the user has enabled passwordless
ssh.
I did think about falling back to one ssh connection at a time in this
case, but it would have needed a rework of every ssh call, which
seems far overboard for such a niche problem. There's no single place where
git-annex runs ssh, so no one place that it could block a concurrent call
on a semaphore. And, even if it did fall back to one ssh connection at a
time, it seems to me that doing so without warning the user about the
problem just invites bug reports like "git-annex is ignoring my -J2 and
only doing one download at a time". So a warning is needed, and I suppose
is good enough.
~/.profile works for bash, but not all other login shells.
This setting PATH is a minor convenience for users, particuarly since
typing on android is so much harder. The usual linux standalone bundle
just expects the user to know how to add it to PATH. I don't want this
code to grow special cases for every possible login shell. So displaying a
message to the presumably minority who don't use bash seems like the best
choice.
Longer term, I'd hope termux gets some way to set an environment variable
for all login shells. Systems using PAM can, via ~/.pam_environment. Or
alternatively, add a git-annex package to termux, even if just an installer
package. I'd rather spend time on either of those than on making this minor
thing support more login shells.
This commit was sponsored by mo on Patreon.
This is to work around https://github.com/datalad/datalad/issues/2769
which I don't know how to reproduce outside that environment, nor do I
understand the root cause of. For some time, Neurodebian has been working
around it by building its standalone debs with a patch that disables use
of the locales bundled with the standalone build, letting the system
locales be used.
Using the system locales is asking for trouble if there's
significant version skew between the system and bundled glibc, and
possibly also if the architeciture is different, or whatever. That's why
git-annex bundles and uses its own locales, because numerous users
reported real problems with using the system locales.
... However, in the specific case of the Neurodebian standalone debs,
the deb is built on a system very like the one it's targeted to be
installed on. Or well, so they assure me, although doc/install/Ubuntu.mdwn
also promotes those for use across all versions of Ubuntu, and the deb
is built avoiding xz so it will work with old versions of dpkg, so I wonder
how true it is. It does seem that, at least currently, there is no bad
version skew in the locales of the systems the deb is used on, since
it's already been using the system locales for some time.
Anyway, since the Neurodebian build already is setting
GIT_ANNEX_PACKAGE_INSTALL=1 in runshell, I made runshell use system
locales when that's set. This is a small scope creep for
GIT_ANNEX_PACKAGE_INSTALL, but it's not documented and AFAIK only used
for the Neurodebian build, so that seems ok. This will let them stop
carrying their patch for this forward.
This work is supported by the NIH-funded NICEMAN (ReproNim TR&D3) project.
The bundled uname -o says Linux in termux; have runshell on Android
delete it so the termux one is used instead.
This fixes the webapp so it will enter Android mode.
This commit was sponsored by mo on Patreon.
* Added arm64 Linux standalone build. (No autobuilder yet.)
* Improved termux installation process.
Added git-annex-install.sh script to avoid user needing to type as much in
termux. The scope of this script is limited; runshell handles the rest.
Runshell runs termux-fix-shebang on the shell scripts. The problem is
the bundled bin/sh script, deleting that script also works, but then the
others probably use the system Android /bin/sh, which could be old or
broken or not posix or whatever. Using termux sh to run the scripts is
better.
This commit was sponsored by Eric Drechsel on Patreon.
On android arm64, I saw the cp fail with "Bad system call", because proot
has not run yet. runshell only recently started using cp, and it's bundled
with git-annex, so this fixes a reversion.
This commit was sponsored by Nick Piper on Patreon.
It can be set to an empty string to use the system locales too. Of course
whether that will work depends on the amount of divergence.
This commit was supported by the NSF-funded DataLad project.
linux standalone: Generate locale files in ~/.cache/git-annex/locales/ so
they're available even when the standalone tarball is installed in a
directory owned by root.
This avoids a full-on reference counting cleanup hell, by letting old
locale caches linger as long as the standalone bundle directory associated
with them is still around. Old ones get cleaned up.
In the case where the directory has a new bundle unpacked over top of it,
the old locale cache is invalidated and rebuilt. Of course, running
programs using that may get confused, but this was already the case, and
unpacking over top of a bundle is probably not a good idea anyhow.
To support that, added a buildid file, which only needs to be unique across
builds of git-annex with different libc versions. sha1sum of git-annex
seems good enough for that.
Removed debian/patches/standalone-no-LOCPATH as it's no longer
necessary.
This commit was supported by the NSF-funded DataLad project.
runshell: Use proot when running on Android, to work around Android 8's
ill-advised seccomp filtering of system calls, including ones crucial for
reliable thread locking. (This will only work with termux's version of
proot.)
See https://github.com/termux/termux-packages/issues/420#issuecomment-386636938
This commit was sponsored by andrea rota.
runshell followed by git annex webapp didn't install that stuff, because
GIT_ANNEX_APP_BASE is not set. Running git-annex.linux/git-annex-webapp did
install that stuff, since that script set the env var. I noticed this with
the termux port whose instructions currently go that way.
Seems the right thing to do is to move the env var setting to runshell.
Added some tweaks to make git-annex work in termux on Android. The regular
arm standalone tarball now works in termux.
I guess the test for "$base/bin/git" is not really necessary, since it
tests for git-annex. Since that gets deleted on android, removed that test.
These are pretty hackish hacks, especially adding it to PATH. The goal is
to make it work well enough out of the box on Android.
This commit was sponsored by Eric Drechsel on Patreon.
Preloaded libraries from the host system may not get along with the bundled
linker.
This was observed by users in termux:
ERROR: ld.so: object '/data/data/com.termux/files/usr/lib/libtermux-exec.so' from LD_PRELOAD cannot be preloaded (wrong ELF class:
ELFCLASS64): ignored.
Bad system call
But it could also affect more usual systems; the preloaded library might rely
on symbols from the host libc that are not available or have the wrong versions
in the bundled libc. Unsetting LD_PRELOAD entirely seems safest.
Currently only done for utf-8 locales because the charset can easily be
told for those. Other locales don't include the charset in their name.
The locale definition is generated under git-annex.linux/locales.
So, this only works if the user can write there.
If locale generation fails for any reason, it's silently skipped.
The git-annex-standalone.deb installs the bundle under /usr, so this locale
generation won't work for non-root users.
Version mismatches between the system locale-archive and the glibc in the
bundle have been observed to cause git crashes.
Unfortunately, this causes locales to not be used in the linux standalone
bundle, as was the case until version 6.20160419.
glibc hardcodes the path to /usr/lib/locale/locale-archive and does not
let an environment variable cause a different locale-archive file to be used.
The only other option to include locales in the bundle would be to include
exploded locale definition directories in the bundle for a number of
locales, generated by localedef. But these take at least 300 kb per locale,
and there are a great many locales; it would be hundreds of megabytes to
include them all.
(Hmm, we could include localdef in the bundle, and check LANG in runshell
and compile the locale directories on the fly. This would need
/usr/share/i18n/ and /usr/lib/locale-archive to be included in the bundle.
It's.. doable.)
I know this is going to once again cause users of the bundle to complain
that eg, ls doesn't show their unicode filenames right. Better than strange
crashes though.
This was introduced by commit 450ee53ab6
However, the same problem could affect other calls to programPath,
specifically some on the assistant. So, I fixed it at a deeper level.
