g.extension crashed with FileNotFoundError in _execute_child(): [Errno 2] No such file or directory: 'svn'

[TMC]

Grass v.7.8.2
Ubuntu 20.04.3

Using grass_gui, attempted to install extension 'r.in.usgs'. Results returned 'FileNotFoundError' then application crashed.

###
(Fri Jan 7 11:24:18 2022)
g.extension --verbose extension=r.in.usgs
Fetching <r.in.usgs> from GRASS GIS Addons repository (be patient)...
Downloading source code for <r.in.usgs> from <https://github.com/OSGeo/grass-addons/trunk/grass7/raster/r.in.usgs> which is identified as 'official' type of source...
Traceback (most recent call last):
  File "/usr/lib/grass78/scripts/g.extension", line 1976, in
<module>
    sys.exit(main())
  File "/usr/lib/grass78/scripts/g.extension", line 1956, in
main
    install_extension(source=source, url=url, xmlurl=xmlurl)
  File "/usr/lib/grass78/scripts/g.extension", line 681, in
install_extension
    ret1, installed_modules, tmp_dir =
install_extension_std_platforms(module,
  File "/usr/lib/grass78/scripts/g.extension", line 1292, in
install_extension_std_platforms
    download_source_code(source=source, url=url, name=name,
  File "/usr/lib/grass78/scripts/g.extension", line 1233, in
download_source_code
    download_source_code_official_github(url, name, outdev,
directory)
  File "/usr/lib/grass78/scripts/g.extension", line 1119, in
download_source_code_official_github
    if grass.call(['svn', 'export',
  File "/usr/lib/grass78/etc/python/grass/script/core.py",
line 74, in call
    return Popen(*args, **kwargs).wait()
  File "/usr/lib/grass78/etc/python/grass/script/core.py",
line 63, in __init__
    subprocess.Popen.__init__(self, args, **kwargs)
  File "/usr/lib/python3.8/subprocess.py", line 858, in
__init__
    self._execute_child(args, executable, preexec_fn,
close_fds,
  File "/usr/lib/python3.8/subprocess.py", line 1704, in
_execute_child
    raise child_exception_type(errno_num, err_msg,
err_filename)
FileNotFoundError: [Errno 2] No such file or directory:
'svn'
(Fri Jan 7 11:24:19 2022) Command finished (0 sec)
##

ProblemType: Crash
DistroRelease: Ubuntu 20.04
Package: grass-core 7.8.2-1build3
ProcVersionSignature: Ubuntu 5.11.0-44.48~20.04.2-generic 5.11.22
Uname: Linux 5.11.0-44-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.21
Architecture: amd64
CasperMD5CheckResult: skip
CrashCounter: 1
CurrentDesktop: XFCE
Date: Fri Jan 7 11:24:19 2022
ExecutablePath: /usr/lib/grass78/scripts/g.extension
InstallationDate: Installed on 2021-11-12 (55 days ago)
InstallationMedia: Xubuntu 20.04.3 LTS "Focal Fossa" - Release amd64 (20210819.1)
InterpreterPath: /usr/bin/python3.8
ProcCmdline: /usr/bin/python3 /usr/lib/grass78/scripts/g.extension --verbose extension=r.in.usgs
Python3Details: /usr/bin/python3.8, Python 3.8.10, python3-minimal, 3.8.2-0ubuntu2
PythonArgs: ['/usr/lib/grass78/scripts/g.extension', '--verbose', 'extension=r.in.usgs']
PythonDetails: N/A
SourcePackage: grass
Title: g.extension crashed with FileNotFoundError in _execute_child(): [Errno 2] No such file or directory: 'svn'
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin lxd plugdev sambashare sudo users
mtime.conffile..etc.apport.crashdb.conf: 2021-12-14T10:49:27.421187

[Markus Neteler (neteler)]

The reason is that the GRASS GIS Addons repository has been restructured in 2021 to distinguish GRASS GIS 7 from the new version 8.

Hence,

`Downloading source code for <r.in.usgs> from <https://github.com/OSGeo/grass-addons/trunk/grass7/raster/r.in.usgs>`

is no longer a valid path, the new path is:

https://github.com/OSGeo/grass-addons/tree/grass7/src/raster/r.in.usgs

Possibilities for you:
a) you use GRASS GIS 7.8.2 which is fairly old. Please update as `g.extension` has been updated accordingly to use the new path in later versions (starting from GRASS GIS 7.8.6).
b) if that's not possible, you may edit your local `g.extension` file in `/usr/lib64/grass78/scripts/g.extension`, using the changes provided here: https://github.com/OSGeo/grass/pull/1762

See also:

https://trac.osgeo.org/grass/wiki/Release/7.8.6-News#Majormodulechanges
- G78:g.extension: updated to match new addon repository structure (​PR:1762)

[Markus Neteler (neteler)]

In essence, it has already been fixed in GRASS GIS 7.8.6.