fix(android): Preserve custom Throwable identities - #5881
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sentry-junior[bot] wants to merge 2 commits into
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fix(android): Preserve custom Throwable identities#5881sentry-junior[bot] wants to merge 2 commits into
sentry-junior[bot] wants to merge 2 commits into
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Co-Authored-By: Roman Zavarnitsyn <roman.zavarnitsyn@sentry.io>
📲 Install BuildsAndroid
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romtsn
marked this pull request as ready for review
July 31, 2026 07:58
romtsn
requested review from
0xadam-brown,
adinauer,
markushi,
romtsn and
runningcode
as code owners
July 31, 2026 07:58
Contributor
Performance metrics 🚀
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| Revision | Plain | With Sentry | Diff |
|---|---|---|---|
| 6b019b7 | 343.31 ms | 417.23 ms | 73.91 ms |
| d15471f | 342.08 ms | 415.44 ms | 73.35 ms |
| 8687935 | 332.52 ms | 362.23 ms | 29.71 ms |
| 5b1a06b | 352.27 ms | 413.70 ms | 61.43 ms |
| 91bb874 | 314.47 ms | 440.00 ms | 125.53 ms |
| 0ee65e9 | 321.06 ms | 361.24 ms | 40.18 ms |
| e63ad34 | 323.67 ms | 390.33 ms | 66.67 ms |
| 33a08cc | 267.08 ms | 340.45 ms | 73.37 ms |
| 27d7cf8 | 397.90 ms | 498.65 ms | 100.75 ms |
| ee747ae | 405.43 ms | 485.70 ms | 80.28 ms |
App size
| Revision | Plain | With Sentry | Diff |
|---|---|---|---|
| 6b019b7 | 0 B | 0 B | 0 B |
| d15471f | 1.58 MiB | 2.13 MiB | 559.54 KiB |
| 8687935 | 1.58 MiB | 2.19 MiB | 619.17 KiB |
| 5b1a06b | 0 B | 0 B | 0 B |
| 91bb874 | 1.58 MiB | 2.13 MiB | 559.07 KiB |
| 0ee65e9 | 0 B | 0 B | 0 B |
| e63ad34 | 0 B | 0 B | 0 B |
| 33a08cc | 1.58 MiB | 2.12 MiB | 555.28 KiB |
| 27d7cf8 | 1.58 MiB | 2.12 MiB | 549.42 KiB |
| ee747ae | 1.58 MiB | 2.10 MiB | 530.95 KiB |
markushi
reviewed
Jul 31, 2026
| # Preserve distinct runtime identities for custom Throwables. R8 horizontal class merging can | ||
| # otherwise merge unrelated exception classes, causing the runtime type and retraced frames to | ||
| # disagree. Unused Throwables may still be removed, and retained Throwables may still be obfuscated. | ||
| -keep,allowshrinking,allowobfuscation class * extends java.lang.Throwable |
Member
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Shouldn't this be just -keepnames (which should be short for Short for -keep,allowshrinking)?
Suggested change
| -keep,allowshrinking,allowobfuscation class * extends java.lang.Throwable | |
| -keepnames class * extends java.lang.Throwable |
Member
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I think the idea here is to allow obfuscating the class as well, and keepnames would disable that
| # Preserve distinct runtime identities for custom Throwables. R8 horizontal class merging can | ||
| # otherwise merge unrelated exception classes, causing the runtime type and retraced frames to | ||
| # disagree. Unused Throwables may still be removed, and retained Throwables may still be obfuscated. | ||
| -keep,allowshrinking,allowobfuscation class * extends java.lang.Throwable |
Member
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We definitely need to check that R8 doesn't flag us here
Member
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it likely does, but there's no other way to work this around, so 🤷 every crash reporter is prone to this issue. But I will check with the R8 config analyzer
runningcode
approved these changes
Aug 4, 2026
| # https://developer.android.com/studio/build/shrink-code#decode-stack-trace | ||
| -keepattributes LineNumberTable,SourceFile | ||
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| # Preserve distinct runtime identities for custom Throwables. R8 horizontal class merging can |
Contributor
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You said in the PR description that this was recommended by the R8 maintainers, do you have a link to that so that we can reference it in this comment?
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Prevent R8 horizontal class merging from collapsing unrelated custom
Throwablesubclasses into one runtime type. This keeps captured exception types aligned with retraced constructor frames and avoids incorrect issue titles or grouping.Consumer ProGuard rule
sentry-android-corenow exports a broad rule that preserves distinct throwable class identities while still allowing unused classes to be removed and retained classes to be obfuscated:The rule follows the mitigation recommended by the R8 maintainers.
Requested by Roman Zavarnitsyn.
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