[Ubuntu] ubuntugis-unstable: gdal_merge.py missing? [PYTHON]PATH to be set?

[Martin Weis]

Hi,

I am missing gdal_merge.py and wonder how to install it. It should
either be in gdal-bin or python[3]-gdal according to what I could find
out. apt-file lists it, maybe it got the source list from ubuntu version?

apt-file search gdal_merge.py
gdal-bin: /usr/bin/gdal_merge.py

It is listed in the package for focal:
https://packages.ubuntu.com/focal/amd64/gdal-bin/filelist

I use ubuntugis-unstable:

apt-cache policy gdal-bin
> gdal-bin:
>   Installed: 3.3.2+dfsg-2~focal1
>   Candidate: 3.3.2+dfsg-2~focal1
>   Version table:
>  *** 3.3.2+dfsg-2~focal1 500
>         500 http://ppa.launchpad.net/ubuntugis/ubuntugis-unstable/ubuntu focal/main amd64 Packages
>         100 /var/lib/dpkg/status
>      3.0.4+dfsg-1build3 500
>         500 http://de.archive.ubuntu.com/ubuntu focal/universe amd64 Packages

but it is not available in gdal-bin package of ubuntu-gis (only a
bashcompletion file):

dpkg -L gdal-bin| grep gdal_merge.py
> /usr/share/bash-completion/completions/gdal_merge.py
apt install python3-gdal # according to policy I get it from
ubuntugis-unstable
> python3-gdal is already the newest version (3.3.2+dfsg-2~focal1).

dpkg -L python3-gdal| grep gdal_merge.py
> /usr/lib/python3/dist-packages/osgeo_utils/gdal_merge.py

ll /usr/lib/python3/dist-packages/osgeo_utils/gdal_merge.py
> -rw-r--r-- 1 root root 17867 Sep  1 11:48
/usr/lib/python3/dist-packages/osgeo_utils/gdal_merge.py

I finally want to be able to use it from within QGIS, there I get

> GDAL command:
> gdal_merge.py -ot Float32 -of GTiff -o /tmp/processing_ncNmOZ/b09ba68e72f84752968b5d6641cbe792/OUTPUT.tif --optfile /tmp/processing_ncNmOZ/e4c573d300fb448aba84c3cb97921d4b/mergeInputFiles.txt
> GDAL command output:
> Process gdal_merge.py failed to start. Either gdal_merge.py is missing, or you may have insufficient permissions to run the program.
> Execution failed after 0.13 seconds

Since the file is not set executable (x), setting PATH or PYTHONPATH
won't help. Do you have any suggestions how to integrate it correctly
into the system?

Thank you,
Martin