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<div class="content">

<h3 style="margin-top: 20px; margin-bottom: 10px;">
Matthew Pickering pushed to branch wip/only_job at <a href="https://gitlab.haskell.org/ghc/ghc">Glasgow Haskell Compiler / GHC</a>
</h3>
<h4 style="margin-top: 10px; margin-bottom: 10px;">
Commits:
</h4>
<ul>
<li>
<strong style="font-weight: 600;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/876d6e0e807c074d5c71370aa3c3451bbcb28342">876d6e0e</a></strong>
<div>
<span> by Ben Gamari </span> <i> at 2024-10-04T15:07:53+01:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","Menlo","DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>base: Add `HasCallStack` constraint to `ioError`

As proposed in core-libraries-committee#275.
</pre>
</li>
<li>
<strong style="font-weight: 600;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/9bfd9fd0730359b4e88e97b08d3654d966a9a11d">9bfd9fd0</a></strong>
<div>
<span> by Matthew Pickering </span> <i> at 2024-10-04T15:08:03+01:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","Menlo","DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Fix toException method for ExceptionWithContext

Fixes #25235
</pre>
</li>
<li>
<strong style="font-weight: 600;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/ac0040286a8962b728a7cdb3c1be4691db635366">ac004028</a></strong>
<div>
<span> by Matthew Pickering </span> <i> at 2024-10-04T15:09:07+01:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","Menlo","DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Exception rethrowing

Basic changes:

* Change `catch` function to propagate exceptions using the
  WhileHandling mechanism.
* Introduce `catchNoPropagate`, which does the same as before, but
  passes an exception which can be rethrown.
* Introduce `rethrowIO` combinator, which rethrows an exception with a
  context and doesn't add a new backtrace.
* Introduce `tryWithContext` for a variant of `try` which can rethrow
  the exception with it's original context.
* onException is modified to rethrow the original error rather than
  creating a new callstack.
* Functions which rethrow in GHC.Internal.IO.Handle.FD,
  GHC.Internal.IO.Handle.Internals, GHC.Internal.IO.Handle.Text, and
  GHC.Internal.System.IO.Error are modified to not add a new callstack.

Implements CLC proposal#202 <https://github.com/haskell/core-libraries-committee/issues/202>
</pre>
</li>
<li>
<strong style="font-weight: 600;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/bcb293f216e56c8dfd199f990e8eaa48071ef845">bcb293f2</a></strong>
<div>
<span> by Cheng Shao </span> <i> at 2024-10-04T17:59:28-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","Menlo","DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>testsuite: remove accidentally checked in debug print logic
</pre>
</li>
<li>
<strong style="font-weight: 600;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/68e2da5a9ed2f0221b0b17a19032d909a1ea1037">68e2da5a</a></strong>
<div>
<span> by Rodrigo Mesquita </span> <i> at 2024-10-05T10:36:15-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","Menlo","DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Deprecation for WarnCompatUnqualifiedImports

Fixes #25330
</pre>
</li>
<li>
<strong style="font-weight: 600;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/4327f0e8c5091dae9ab0f58e2e3c8af5bacd12ea">4327f0e8</a></strong>
<div>
<span> by Andrew Lelechenko </span> <i> at 2024-10-05T10:36:52-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","Menlo","DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Restrict Data.List.NonEmpty.unzip to NonEmpty (a, b) -> (NonEmpty a, NonEmpty b)

Implementing the final phase of CLC proposal https://github.com/haskell/core-libraries-committee/issues/86
</pre>
</li>
<li>
<strong style="font-weight: 600;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/ceca9efb3d437fb74263877d98d4fb4a45ee96b8">ceca9efb</a></strong>
<div>
<span> by Cheng Shao </span> <i> at 2024-10-06T02:18:31+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","Menlo","DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>driver: fix runWorkerLimit on wasm

This commit fixes link-time unresolved symbol errors for sem_open etc
on wasm, by making runWorkerLimit always behave single-threaded. This
avoids introducing the jobserver logic into the final wasm module and
thus avoids referencing the posix semaphore symbols.
</pre>
</li>
<li>
<strong style="font-weight: 600;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/135fd1ac9212ba7d3517e4e4c0bf85bf247ac3b3">135fd1ac</a></strong>
<div>
<span> by Torsten Schmits </span> <i> at 2024-10-06T02:18:31+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","Menlo","DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Parallelize getRootSummary computations in dep analysis downsweep

This reuses the upsweep step's infrastructure to process batches of
modules in parallel.

I benchmarked this by running `ghc -M` on two sets of 10,000 modules;
one with a linear dependency chain and the other with a binary tree.
Comparing different values for the number of modules per thread
suggested an optimum at `length targets `div` (n_cap * 2)`, with results
similar to this one (6 cores, 12 threads):

```
Benchmark 1: linear 1 jobs
  Time (mean ± σ):      1.775 s ±  0.026 s    [User: 1.377 s, System: 0.399 s]
  Range (min … max):    1.757 s …  1.793 s    2 runs

Benchmark 2: linear 6 jobs
  Time (mean ± σ):     876.2 ms ±  20.9 ms    [User: 1833.2 ms, System: 518.6 ms]
  Range (min … max):   856.2 ms … 898.0 ms    3 runs

Benchmark 3: linear 12 jobs
  Time (mean ± σ):     793.5 ms ±  23.2 ms    [User: 2318.9 ms, System: 718.6 ms]
  Range (min … max):   771.9 ms … 818.0 ms    3 runs
```

Results don't differ much when the batch size is reduced to a quarter
of that, but there's significant thread scheduling overhead for a size
of 1:

```
Benchmark 1: linear 1 jobs
  Time (mean ± σ):      2.611 s ±  0.029 s    [User: 2.851 s, System: 0.783 s]
  Range (min … max):    2.591 s …  2.632 s    2 runs

Benchmark 2: linear 6 jobs
  Time (mean ± σ):      1.189 s ±  0.007 s    [User: 2.707 s, System: 1.103 s]
  Range (min … max):    1.184 s …  1.194 s    2 runs

Benchmark 3: linear 12 jobs
  Time (mean ± σ):      1.097 s ±  0.006 s    [User: 2.938 s, System: 1.300 s]
  Range (min … max):    1.093 s …  1.101 s    2 runs
```

Larger batches also slightly worsen performance.
</pre>
</li>
<li>
<strong style="font-weight: 600;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/535a2117239f0d0e4588c6616fcd8deed725cfc0">535a2117</a></strong>
<div>
<span> by Daniel Díaz </span> <i> at 2024-10-06T09:51:46-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","Menlo","DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Clarify the meaning of "exactly once" in LinearTypes

Solves documentaion issue #25084.
</pre>
</li>
<li>
<strong style="font-weight: 600;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/92f8939a5fa689dc0143501cfeac0b3b2cd7abd6">92f8939a</a></strong>
<div>
<span> by Krzysztof Gogolewski </span> <i> at 2024-10-06T09:52:22-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","Menlo","DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Only allow (a => b) :: Constraint rather than CONSTRAINT rep

Fixes #25243
</pre>
</li>
<li>
<strong style="font-weight: 600;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/4a2f0f1302f5919dfc9c8cbc410fceb19e7309ba">4a2f0f13</a></strong>
<div>
<span> by Alan Zimmerman </span> <i> at 2024-10-07T05:16:54-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","Menlo","DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>EPA: Remove unused hsCaseAnnsRest

We never populate it, so remove it.
</pre>
</li>
<li>
<strong style="font-weight: 600;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5099057b7eaa08d53c8ab07be0f6d626496ec79d">5099057b</a></strong>
<div>
<span> by John Paul Adrian Glaubitz </span> <i> at 2024-10-07T05:17:40-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","Menlo","DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>rts: Fix invocation of __ieee_set_fp_control() on alpha-linux

Fixes the following error when building GHC on alpha-linux:

rts/posix/Signals.c: In function ‘initDefaultHandlers’:

rts/posix/Signals.c:709:5: error:
     error: implicit declaration of function ‘ieee_set_fp_control’ [-Wimplicit-function-declaration]
      709 |     ieee_set_fp_control(0);
          |     ^~~~~~~~~~~~~~~~~~~
    |
709 |     ieee_set_fp_control(0);
    |
</pre>
</li>
<li>
<strong style="font-weight: 600;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/c9590ba0703d65ecb9d71ac8390c1ae1144bd9d0">c9590ba0</a></strong>
<div>
<span> by Teo Camarasu </span> <i> at 2024-10-07T05:18:17-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","Menlo","DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Add changelog entries for !12479
</pre>
</li>
<li>
<strong style="font-weight: 600;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/67bb80210c19630b7297d75ce9e21745ec486c05">67bb8021</a></strong>
<div>
<span> by Matthew Pickering </span> <i> at 2024-10-07T16:42:55+01:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","Menlo","DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>ci: Add support for ONLY_JOBS variable to trigger any validation pipeline

By setting the ONLY_JOBS variable to the name of the job (or multiple
jobs), the resulting
pipeline will include a validation job for that pipeline.

For example - if you set ONLY_JOBS="x86_64-linux-ubuntu22_04-validate"
then a ubuntu22_04 job will be included in the validation pipeline. This
is useful for testing specific jobs.

Fixes #25332
</pre>
</li>
</ul>
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compiler/GHC/Driver/Flags.hs
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compiler/GHC/Driver/Make.hs
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compiler/GHC/Driver/Session.hs
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compiler/GHC/Hs/Expr.hs
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compiler/GHC/Parser.y
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