Psalm 5 cache is unstable

[jack-worman]

The follow has been frustrating:

1. Clear psalm cache
2. Run psalm and get no errors
3. Do any change (even adding a blank line)
4. Run psalm and get errors in totally unrelated files. Seems like mostly unused errors: UnusedProperty, PossiblyUnusedMethod, PossiblyUnusedProperty

[weirdan]

@kkmuffme you've done a lot of work on caching lately, perhaps this may interest you.

[kkmuffme]

Please create a reproduction repo

I can't reproduce this issue in our environment atm

[jack-worman]

Trying to work on a reproduction repo, but seems hard to reproduce.

But something I just noticed, all the issues it is reporting are in the baseline. So something about using the cache causes the baselined issues to not be ignored.

[weirdan]

I did see a similar issue in Psalm's own codebase.

[weirdan]

> ./psalm  # run with a cache, no files changed
Target PHP version: 7.4 (inferred from composer.json) Extensions enabled: dom, simplexml (unsupported extensions: ctype, json, libxml, mbstring, tokenizer)
Scanning files...
Analyzing files...



------------------------------

       No errors found!

------------------------------
217 other issues found.
You can display them with --show-info=true
------------------------------

Checks took 0.13 seconds and used 68.385MB of memory
No files analyzed
Psalm was able to infer types for 99.8722% of the codebase

> vim src/Psalm/Config.php # edit the file - I just added a bunch of empty lines in `use` block

> ./psalm  # run Psalm again
Target PHP version: 7.4 (inferred from composer.json) Extensions enabled: dom, simplexml (unsupported extensions: ctype, json, libxml, mbstring, tokenizer)
Scanning files...
Analyzing files...

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ERROR: PossiblyUnusedProperty - src/Psalm/Type/MutableUnion.php:86:12 - Cannot find any references to property Psalm\Type\MutableUnion::$initialized_class (see https://psalm.dev/149)
    public $initialized_class;


ERROR: PossiblyUnusedProperty - src/Psalm/Type/MutableUnion.php:98:12 - Cannot find any references to property Psalm\Type\MutableUnion::$failed_reconciliation (see https://psalm.dev/149)
    public $failed_reconciliation = false;


ERROR: PossiblyUnusedProperty - src/Psalm/Type/MutableUnion.php:157:12 - Cannot find any references to property Psalm\Type\MutableUnion::$from_template_default (see https://psalm.dev/149)
    public $from_template_default = false;


ERROR: PossiblyUnusedProperty - src/Psalm/Type/MutableUnion.php:186:12 - Cannot find any references to property Psalm\Type\MutableUnion::$by_ref (see https://psalm.dev/149)
    public $by_ref = false;


ERROR: PossiblyUnusedProperty - src/Psalm/Type/MutableUnion.php:191:12 - Cannot find any references to property Psalm\Type\MutableUnion::$reference_free (see https://psalm.dev/149)
    public $reference_free = false;


ERROR: PossiblyUnusedProperty - src/Psalm/Type/MutableUnion.php:196:12 - Cannot find any references to property Psalm\Type\MutableUnion::$allow_mutations (see https://psalm.dev/149)
    public $allow_mutations = true;


ERROR: PossiblyUnusedProperty - src/Psalm/Type/MutableUnion.php:201:12 - Cannot find any references to property Psalm\Type\MutableUnion::$has_mutations (see https://psalm.dev/149)
    public $has_mutations = true;


ERROR: PossiblyUnusedProperty - src/Psalm/Type/Union.php:132:12 - Cannot find any references to property Psalm\Type\Union::$ignore_isset (see https://psalm.dev/149)
    public $ignore_isset = false;


------------------------------
8 errors found
------------------------------
217 other issues found.
You can display them with --show-info=true
------------------------------

Checks took 4.53 seconds and used 948.602MB of memory
Psalm was able to infer types for 99.8690% of the codebase

The change I introduced was real trivial:

diff --git a/src/Psalm/Config.php b/src/Psalm/Config.php
index ee172a430..88c831d8c 100644
--- a/src/Psalm/Config.php
+++ b/src/Psalm/Config.php
@@ -4,6 +4,15 @@ namespace Psalm;

 use Composer\Autoload\ClassLoader;
 use Composer\Semver\Constraint\Constraint;
+
+
+
+
+
+
+
+
+
 use Composer\Semver\VersionParser;
 use DOMAttr;
 use DOMDocument;

[kkmuffme]

@weirdan so the problem is with the baseline? (I assume those errors are ignored via psalm's baseline?)

If yes, I can't help much, bc we don't use a baseline and I'm in crunch time until January

[weirdan]

Yes, all of those are ignored through the baseline (and it's the only occurrences of UnusedProperty we have there).

[weirdan]

Turns out there are no problems with the baseline itself. The Psalm emits (almost) the same error twice in this case, and baseline correctly suppresses only one occurrence:

ERROR: PossiblyUnusedProperty - src/Psalm/Type/MutableUnion.php:86:12 - Cannot find explicit references to property Psalm\Type\Mutabl
eUnion::$initialized_class (but did find some potential references) (see https://psalm.dev/149)
    public $initialized_class;


ERROR: PossiblyUnusedProperty - src/Psalm/Type/MutableUnion.php:86:12 - Cannot find any references to property Psalm\Type\MutableUnio
n::$initialized_class (see https://psalm.dev/149)
    public $initialized_class;