HotSpot Error Report (hs_err) for VS Code
Syntax highlighting for HotSpot crash report files such as hs_err_pid*.log to let you read and navigate them more easily. The grammar is tuned for real hs_err files, covering signals, threads, stack frames, registers (x86/ARM/PPC/s390x), heap, GC, NMT, and all other sections found in real hs_err files.
This extension is part of the main jhserr project:
https://github.com/parttimenerd/jhserr
Install
Install from VS Code Marketplace:
https://marketplace.visualstudio.com/items?itemName=bechberger.hserr-syntax
What You Get
Syntax highlighting tuned for real hs_err files — everything is colour-coded so
you can scan a crash report at a glance:
| Element |
Examples |
| Section banners |
--- T H R E A D ---, --- P R O C E S S --- |
| Subsection headings |
Registers:, Heap:, Native frames:, Events (20 events): |
| Crash signals & error types |
SIGSEGV, Internal Error, Out of Memory Error |
| Stack frames |
V / C / J / j / v frame types, compile tier (c1 / c2) |
| Java class & method names |
java.lang.Thread.run, LambdaForm$MH+0x… |
| C++ symbols |
ShenandoahHeap::allocate_memory, os::Linux::ucontext_get_pc |
| Shared libraries |
libjvm.so, libpthread.so.0 |
| Addresses & hex values |
0x00007fff…, register values, hex dumps |
| Registers |
RAX, RBX, x0–x28, r0–r31, etc. |
| Thread names & states |
"main", _thread_in_vm, _thread_blocked |
| VM flags & options |
-XX:+UseG1GC, -Xmx384M, -Djava.io.tmpdir=… |
| GC, NMT, event-log entries |
nmethod, Loading, Unloading, DEOPT, GC phase timings |
| Assertions & fatal errors |
assert(…) failed:, guarantee(…) failed: |
| Paths, URLs, versions |
file paths, https://…, JRE/JVM version strings |
| Numeric literals |
integers, floats, sizes (2048K), timestamps |
Navigation — the Outline / Breadcrumb bar shows every section and
subsection so you can jump straight to Registers, Heap, Event logs, etc.
Folding — collapse sections, subsections, the # header block, and
code-blob disassembly blocks.
Auto-detection — files with non-standard names (not hs_err_pid*.log)
are automatically recognised as hs_err if they contain the characteristic
header and section banners.
File icons for common hs_err filenames.
Build and Package (local)
Marketplace page:
https://marketplace.visualstudio.com/items?itemName=bechberger.hserr-syntax
cd vscode-plugin
npm install
npm run compile
npm run package
Install the generated VSIX locally:
code --install-extension hserr-syntax-*.vsix
Use the browser-based parser/redaction tool here:
https://parttimenerd.github.io/jhserr/
Support, Feedback, Contributing
This project is open to feature requests/suggestions, bug reports etc. via GitHub issues. Contribution and feedback are encouraged and always welcome.
License
MIT, Copyright 2026 SAP SE or an SAP affiliate company, Johannes Bechberger and contributors
