Continuing along the same lines as commit
2739adc258, it seems that
while Remote -> Retriever expands to the same data type this changes
it to, ghc 9.0.1 refuses to consider them equiviant. I guess it has
something to do with the forall?
The rest of the build all succeeds, although the stack build then crashes:
Linking .stack-work/dist/x86_64-linux-tinfo6/Cabal-3.4.0.0/build/git-annex/git-annex ...
Completed 233 action(s).
Prelude.chr: bad argument: 2214592520
This issue seems likely to be about it:
https://github.com/commercialhaskell/stack/pull/5508
I'm building with stack from debian, version 2.3.3, so a newer stack
probably avoids that. Anyway, despite that stack problem,
the git-annex binary is built, and works.
The stack.yaml I used for this build was patched as follows:
diff --git a/stack.yaml b/stack.yaml
index 8dac87c15..62c4b5b9d 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,6 +1,6 @@
flags:
git-annex:
- production: true
+ production: false
assistant: true
pairing: true
torrentparser: true
@@ -14,7 +14,7 @@ flags:
httpclientrestricted: true
packages:
- '.'
-resolver: lts-18.13
+resolver: nightly-2021-09-07
extra-deps:
- IfElse-0.85
- aws-0.22
Sponsored-by: Graham Spencer on Patreon
This fixes a FD leak when annex.pidlock is set and -J is used. Also, it
fixes bugs where the pid lock file got deleted because one thread was
done with it, while another thread was still holding it open.
The LockPool now has two distinct types of resources,
one is per-LockHandle and is used for file Handles, which get closed
when the associated LockHandle is closed. The other one is per lock
file, and gets closed when no more LockHandles use that lock file,
including other shared locks of the same file.
That latter kind is used for the pid lock file, so it's opened by the
first thread to use a lock, and closed when the last thread closes a lock.
In practice, this means that eg git-annex get of several files opens and
closes the pidlock file a few times per file. While with -J5 it will open
the pidlock file, process a number of files, until all the threads happen to
finish together, at which point the pidlock file gets closed, and then
that repeats. So in either case, another process still gets a chance to
take the pidlock.
registerPostRelease has a rather intricate dance, there are fine-grained
STM locks, a STM lock of the pidfile itself, and the actual pidlock file
on disk that are all resolved in stages by it.
Sponsored-by: Dartmouth College's Datalad project
This reverts commit 66b2536ea0.
I misunderstood commit ac56a5c2a0
and caused a FD leak when pid locking is not used.
A LockHandle contains an action that will close the underlying lock
file, and that action is run when it is closed. In the case of a shared
lock, the lock file is opened once for each LockHandle, and only
the one for the LockHandle that is being closed will be closed.
This locking has been missing from the beginning of annex.pidlock.
It used to be possble, when two threads are doing conflicting things,
for both to run at the same time despite using locking. Seems likely
that nothing actually had a problem, but it was possible, and this
eliminates that possible source of failure.
Sponsored-by: Dartmouth College's Datalad project
