[Bug] r.blend (main) fails to create valid data: "Error uncompressing fp raster data for row" #6158
Description
Describe the bug
r.blend in master outputs corrupted data:
r.blend -c first=data1 second=data2 output=data_blend percent=50 --overwrite
Fails with error:
WARNING: Invalid read size 23040
ERROR: Error uncompressing fp raster data for row 105 of
<data.g>: error code -2
Traceback (most recent call last):
File "/usr/local/grass85/scripts/r.blend", line 134, in <module>
main()
~~~~^^
File "/usr/local/grass85/scripts/r.blend", line 105, in main
gs.run_command(
~~~~~~~~~~~~~~^
"r.composite",
^^^^^^^^^^^^^^
...<3 lines>...
output=output,
^^^^^^^^^^^^^^
)
^
File "/usr/local/grass85/etc/python/grass/script/core.py", line 616, in run_command
return handle_errors(returncode, result=None, args=args, kwargs=kwargs)
File "/usr/local/grass85/etc/python/grass/script/core.py", line 461, in handle_errors
raise CalledModuleError(
module=module, code=code, returncode=returncode, errors=stderr
)
Running r.blend without the -c flag does produce output data that cannot be displayed, with error:
Failed to run command 'd.rast map=data_blend.b@s2'. Details:
GRASS_INFO_WARNING(108719,1): Invalid read size 23040
GRASS_INFO_END(108719,1)
GRASS_INFO_ERROR(108719,2): Error uncompressing fp raster data for row 96 of <data_blend.b>: error code -2
GRASS_INFO_END(108719,2)
r.blend is a script involving r.composite. r.composite is running without problems.
This is part of a workflow that was working well 3 or 4 months ago. The error does not occur on GRASS 8.4.1 compiled against the same GDAL.
To reproduce
- use latest GRASS master
- Given two raster datasets,
data1anddata2 - execute
r.blend -c first=data1 second=data2 output=data_blend percent=50 --overwrite - See error
Expected behavior
r.blend should produce valid data
System description
> g.version -rge
version=8.5.0dev
date=2025
revision=9243fb5b04
build_date=2025-08-02
build_platform=x86_64-pc-linux-gnu
build_off_t_size=8
libgis_revision=7469244060
libgis_date=2025-07-29T11:57:21+00:00
proj=9.7.0
gdal=3.12.0dev-15f3e47a1b-dirty
geos=3.14.0beta1
sqlite=3.50.3
> python3 -c "import sys, wx; print(sys.version); print(wx.version())"
3.13.5 (main, Jun 11 2025, 22:06:31) [GCC]
4.2.3 gtk3 (phoenix) wxWidgets 3.2.8