How to help us debug Sumatra hangs or crashes
If Sumatra crashes or hangs reliably on your machine but we
can't reproduce it ourselves, you can help us by debugging
it. Here's a tutorial on how to do it.
Please first test with latest pre-release version from
https://www.sumatrapdfreader.org/prerelease.html
Some bugs might already be fixed there compared to latest
Those instructions require SumatraPDF 3.2 or later.
Install necessary software
- Install WinDBG debugger from Microsoft Store at https://www.microsoft.com/en-us/p/windbg-preview/9pgjgd53tn86#activetab=pivot:overviewtab. Alternatively, you can follow instructions from https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/debugger-download-tools
- In SumatraPDF, use menu
Debug
/Download symbols
. Symbols are important for the debugger (like WinDBG) to resolve addresses to names that
First, vocabulary.
%ProgramFiles%
means the standard
directory where Windows installs programs. It's c:\Program Files
on 32-bit Windows and c:\Program Files (x86)
on
64-bit Windows.Debugging a crash
To debug crashes:
- start SumatraPDF.exe under the control of WinDBG
- start WinDBG.exe
- File/Open (Ctrl-E), find and open SumatraPDF.exe executable
- In WinDBG, type:
.sympath+ SRV*c:\symbols*http://msdl.microsoft.com/download/symbols
g
- when Sumatra crashes, type:
!analyze -v
and paste the result of that to the bug report
Debugging a hang
Here are the steps to follow if Sumatra hangs
- Start SumatraPDF.exe and get it to hang
- start WinDBG.exe
- use File/Attach to process (F6) and select SumatraPDF.exe from the
- In WinDBG, type:
7.1)
.sympath+
SRV*c:\symbols*http://msdl.microsoft.com/download/symbols
7.2)
~*kb
7.3)
lmf
Attach the output to bug report.