Bug#1100657: Magics cannot seem to load its own JSON files

[Enrico Zini]

Package: python3-magics++
Version: 2:1.5.8-3
Severity: important

Hello,

thank you for maintaining Magics.

If I run the attached script, I get:

   $ python3 magics-reproducer
   b'Magics-ERROR: JSON error in file: /usr/lib/python3/dist-packages/ecmwflibs/share/magics/epsg.json: Cannot open file /usr/lib/python3/dist-packages/ecmwflibs/share/magics/epsg.json: X\xa2\xa0\n'
   fish: Job 2, 'python3 /tmp/magics-reproducer' terminated by signal SIGSEGV (Address boundary error)

The file is installed in /usr/share/magics/epsg.json instead.

If I brutally copy the file to
/usr/lib/python3/dist-packages/ecmwflibs/share/magics/epsg.json
then I get a reproducer for what looks like another Magics issue[1] which
is out of scope for this one.


Thanks,

Enrico

[1] https://www.enricozini.org/blog/2021/debian/an-educational-debugging-session/
    which now also seems to apply to Debian stable?

-- System Information:
Debian Release: trixie/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 6.12.12-amd64 (SMP w/16 CPU threads; PREEMPT)
Kernel taint flags: TAINT_WARN
Locale: LANG=en_IE.UTF-8, LC_CTYPE=en_IE.UTF-8 (charmap=UTF-8), LANGUAGE=en_IE:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages python3-magics++ depends on:
ii  python3             3.13.2-2
ii  python3-ecmwflibs   2:0.6.3-2+b1
ii  python3-findlibs    0.0.5-1
ii  python3-jinja2      3.1.5-2
ii  python3-numpy       1:2.2.3+ds-2+b1
ii  python3-simplejson  3.19.3-1+b2

python3-magics++ recommends no packages.

python3-magics++ suggests no packages.

-- no debconf information
-------------- next part --------------
import Magics
from Magics import macro

output = macro.output(output_formats=["png"], output_name="output")
parts = []
parts.append(
    macro.mmap(
	**{
	    "subpage_map_projection": "mercator",
	    "subpage_lower_left_longitude": 5.1,
	    "subpage_lower_left_latitude": 43.0,
	    "subpage_upper_right_longitude": 15.0,
	    "subpage_upper_right_latitude": 47.5,
	    "subpage_map_vertical_longitude": 10.3,
	}
    )
)
parts.append(
    macro.msymb(
	**{
	    "symbol_type": "marker",
	    "symbol_marker_index": 15,
	    "legend": "off",
	    "symbol_colour": "black",
	    "symbol_height": 0.28,
	}
    )
)

macro.plot(output, *parts)