mirror of https://github.com/GNOME/gimp.git
devel-docs: debugging-tips.md also moved to gimp-web-devel repo.
This commit is contained in:
Jehan
parent
0036b190e1
commit
9716768bb1
|
|
@ -1,242 +0,0 @@
|
|||
There are a few environment variables, options or other more-or-less
|
||||
known tricks to debug GIMP. Let's try to add them here for reminder and
|
||||
newcomers.
|
||||
|
||||
## Basics ##
|
||||
|
||||
The basic thing is to build babl, GEGL and GIMP with `--enable-debug`.
|
||||
|
||||
Note that if you also built glib from source with `--enable-debug`,
|
||||
every pointers of destroyed GObject are overwritten with `0xaa` bytes,
|
||||
so dereferencing one after destruction usually leads to a crash, which
|
||||
is a good way to find some more vicious bugs. Also it makes pointers of
|
||||
destroyed data easy to spot.
|
||||
|
||||
## Debug logs ##
|
||||
|
||||
You can see various GIMP_LOG() calls in the code. These will only be
|
||||
outputted when you set GIMP_DEBUG environment variable to a
|
||||
comma-separated list of domain.
|
||||
For instance, for `GIMP_LOG (XCF, "some string")` to be outputted,
|
||||
run GIMP like this:
|
||||
|
||||
> GIMP_DEBUG=xcf gimp-2.10
|
||||
|
||||
Special flags are:
|
||||
- "all" to output all domain logs;
|
||||
- "list-all" to get a list of available domains.
|
||||
|
||||
## Debugging a warning ##
|
||||
|
||||
If you encounter a CRITICAL or WARNING message on console, you can make
|
||||
so that GIMP crashes on it, which will make it very easy to be tracked
|
||||
down in a debugger (for instance GDB), by running GIMP with:
|
||||
|
||||
> gimp-2.10 --g-fatal-warnings
|
||||
|
||||
Note that if all you want is a stacktrace, it is not necessary anymore
|
||||
to use a debugger and --g-fatal-warnings. In Preferences > Debugging,
|
||||
make sure that all type of errors are debugged, and that you have either
|
||||
gdb or lldb installed. Then a graphical dialog will automatically appear
|
||||
upon encountering any WARNING or CRITICAL with backtraces and variable
|
||||
contents.
|
||||
|
||||
Alternatively running GIMP with the CLI option --stack-trace-mode to
|
||||
values "query" or "always" will output a stacktrace too on terminal.
|
||||
But this happens only for crashes, so it still requires to use
|
||||
--g-fatal-warnings for WARNINGs and CRITICALs.
|
||||
|
||||
Note: on Windows, even the debugging GUI happens only for crashes and
|
||||
requires that you built with Dr. Mingw dependency.
|
||||
|
||||
## Debugging GTK ##
|
||||
|
||||
You can use GtkInspector by running GIMP with:
|
||||
|
||||
> GTK_DEBUG=interactive gimp-2.99
|
||||
|
||||
Alternatively you may also start it at anytime with ctrl-shift-d
|
||||
shortcut, if you first enable with:
|
||||
|
||||
> gsettings set org.gtk.Settings.Debug enable-inspector-keybinding true
|
||||
|
||||
See also: https://wiki.gnome.org/Projects/GTK%2B/Inspector
|
||||
|
||||
Note also that running GIMP with `GDK_SCALE=2` (or other values) allow
|
||||
to test the interface in another scaling than your native one. This
|
||||
settings is also available in the GtkInspector.
|
||||
|
||||
## Debugging GEGL code ##
|
||||
|
||||
You may encounter this kind of warning upon exiting GIMP:
|
||||
|
||||
> EEEEeEeek! 2 GeglBuffers leaked
|
||||
|
||||
To debug GeglBuffer leaks, make sure you built GEGL with -Dbuildtype=debug
|
||||
or -Dbuildtype=debugoptimized, and set the environment variable
|
||||
GEGL_DEBUG to "buffer-alloc".
|
||||
Your system also needs to have the header "execinfo.h".
|
||||
|
||||
## Debugging babl ##
|
||||
|
||||
Profile conversion is done with babl by default when possible, which is
|
||||
much faster.
|
||||
Setting GIMP_COLOR_TRANSFORM_DISABLE_BABL environment variable switch
|
||||
back to the old lcms implementation, which can be useful for comparison.
|
||||
|
||||
## Debugging X Window System error ##
|
||||
|
||||
Make X calls synchronous so that your crashes happen immediately with:
|
||||
|
||||
> gimp-2.10 --sync
|
||||
|
||||
You can also break on `gdk_x_error()`.
|
||||
|
||||
## Debugging on Windows ##
|
||||
|
||||
Even when run from a `cmd`, the standard and error outputs are not
|
||||
displayed in the terminal. For this reason, unstable builds (i.e. with
|
||||
odd minor version) pop up a debug console at start.
|
||||
|
||||
If you are building stable versions of GIMP for debugging and want this
|
||||
debug console as well, configure with `--enable-win32-debug-console`.
|
||||
|
||||
## Testing older GIMP versions ##
|
||||
|
||||
A useful trick when you want to quickly test a specific GIMP older
|
||||
version (e.g. to confirm a behavior change) is to install it with our
|
||||
official flatpak. The flathub repository stores past builds (up to 20 at
|
||||
the time of writing). You can list them with the following command:
|
||||
|
||||
```
|
||||
$ flatpak remote-info --log flathub org.gimp.GIMP
|
||||
```
|
||||
|
||||
Each build will have a "Subject" line (a comment to indicate the build
|
||||
reason, it may be just dependency updates or build fixes, or sometimes a
|
||||
bump in GIMP version) and a commit hash. When you have identified the
|
||||
build you want to test, update it like this:
|
||||
|
||||
```
|
||||
flatpak update --commit=<hash-of-build> org.gimp.GIMP
|
||||
```
|
||||
|
||||
Then just run your older GIMP!
|
||||
|
||||
## Debugging on flatpak
|
||||
|
||||
### Generic flatpak abilities
|
||||
|
||||
If you want to inspect the sandbox environment, you can do so by
|
||||
specifying a custom shell instead of the GIMP binary with the following
|
||||
command:
|
||||
|
||||
```
|
||||
flatpak run --command=bash org.gimp.GIMP
|
||||
```
|
||||
|
||||
This will run the exact same environment as the flatpak, which should
|
||||
also be identical on all machines.
|
||||
|
||||
Alternatively you can run the GIMP Flatpak using the GNOME SDK as
|
||||
runtime (instead of the .Platform) with the `--devel` option. In
|
||||
particular, it gives you access to a few additional debug tools, such as
|
||||
`gdb`. Therefore running GIMP with --devel will give better stacktrace,
|
||||
or you can run explicitly GIMP inside GDB.
|
||||
|
||||
Additionally to install debug symbols in the sandbox, run:
|
||||
|
||||
```
|
||||
flatpak install flathub org.gimp.GIMP.Debug
|
||||
flatpak install flathub org.gnome.Sdk.Debug
|
||||
```
|
||||
|
||||
### Getting accurate traces from reported inaccurate traces
|
||||
|
||||
Even with reporter trace without debug symbols (yet debug symbols
|
||||
installed on your side), if you make sure you use exactly the same
|
||||
flatpak commit as the reporter (see `Testing older GIMP versions`
|
||||
section), you are ensured to use the same binaries. Hence you can trace
|
||||
back the code line from an offset.
|
||||
|
||||
For instance, say that your trace has this output:
|
||||
|
||||
```
|
||||
gimp-2.10(file_open_image+0x4e8)[0x5637e0574738]
|
||||
```
|
||||
|
||||
Here is how you can find the proper code line in the Flatpak (provided
|
||||
you use the right flatpak commit):
|
||||
|
||||
```
|
||||
$ RUNTIME_VERSION=$(flatpak run org.gimp.GIMP//stable -v |grep runtime=runtime/org.gnome.Platform/ |sed 's$runtime=runtime/org.gnome.Platform/$$')
|
||||
$ flatpak install flathub org.gimp.GIMP.Debug org.gnome.Sdk/$RUNTIME_VERSION org.gnome.Sdk.Debug/$RUNTIME_VERSION
|
||||
$ flatpak run --devel --command=bash org.gimp.GIMP
|
||||
(flatpak) $ gdb /app/bin/gimp-2.10
|
||||
(gdb) info line *(file_open_image+0x4e8)
|
||||
Line 216 of "file-open.c" starts at address 0x4d5738 <file_open_image+1256> and ends at 0x4d5747 <file_open_image+1271>.
|
||||
```
|
||||
|
||||
### Debugging though gdbserver
|
||||
|
||||
In some cases, when GIMP grabs the pointer and/or keyboard, i.e. when
|
||||
you debug something happening on canvas in particular, it might be very
|
||||
hard to get back to your debugger, since your system won't be responding
|
||||
to your keyboard or click events.
|
||||
|
||||
To work around this, you can debug remotely, or simply from a TTY (while
|
||||
the desktop doesn't answer properly):
|
||||
|
||||
In your desktop, run GIMP through a debugger server:
|
||||
|
||||
```
|
||||
$ flatpak run --devel --command=bash org.gimp.GIMP//beta
|
||||
$ gdbserver :9999 /app/bin/gimp-2.99
|
||||
```
|
||||
|
||||
Go to a TTY and run
|
||||
|
||||
```
|
||||
$ gdb /app/bin/gimp-2.99
|
||||
(gdb) target remote localhost:9999
|
||||
(gdb) continue
|
||||
```
|
||||
|
||||
Of course, before the `continue`, you may add whatever break points or
|
||||
other commands necessary for your specific issue. GIMP will start in the
|
||||
desktop when you hit `continue` (it will likely be a slower start).
|
||||
|
||||
Then do your issue reproduction steps on GIMP. When you need to debug,
|
||||
you can go to the TTY whenever you want, not bothering about any
|
||||
keyboard/pointer grabs.
|
||||
|
||||
Note that since copy-pasting is harder in a TTY, you might want to
|
||||
redirect your output to a file, especially if you need to upload it or
|
||||
read it slowly next to GIMP code. For instance here are commands to
|
||||
output a full backtrace into a file from the gdb prompt and exit (to
|
||||
force the device ungrab by killing GIMP and go work on desktop again):
|
||||
|
||||
```
|
||||
(gdb) set logging file gimp-issue-1234.txt
|
||||
(gdb) set logging on
|
||||
(gdb) thread apply all backtrace full
|
||||
(gdb) quit
|
||||
```
|
||||
|
||||
## Debugging icons ##
|
||||
|
||||
See file `devel-docs/icons.txt` to learn more about our icons, and in
|
||||
particular the environment variable GIMP_ICONS_LIKE_A_BOSS.
|
||||
|
||||
## Debugging plug-ins ##
|
||||
|
||||
See file `devel-docs/debug-plug-ins.txt` for usage of environment
|
||||
variable GIMP_PLUGIN_DEBUG.
|
||||
|
||||
The CLI option --stack-trace-mode also applies to plug-ins, in order to
|
||||
output a back trace on terminal.
|
||||
|
||||
## Performance logs ##
|
||||
|
||||
See file `devel-docs/performance-logs/performance-logs.md` for information
|
||||
about GIMP performance logs, which can help during optimization.
|
||||
Loading…
Reference in New Issue