Backtracker segmentation fault

Q&A
1

I’m encountering some strange behavior with gmt backtracker. I have a set of locations with ages I am trying to backtrack but I keep getting this ERROR: Caught signal number 11 (Segmentation fault: 11) at
0 libsystem_platform.dylib 0x000000018e150864 _platform_strlen + 4
1 ??? 0x0000000000000100 0x0 + 256
Stack backtrace:
0 libgmt.6.4.0.dylib 0x000000010344e6f4 sig_handler_unix + 264
1 libsystem_platform.dylib 0x000000018e1534a4 _sigtramp + 56
2 libsystem_c.dylib 0x000000018dfff6a0 __vfprintf + 4544
3 libsystem_c.dylib 0x000000018e02d764 _vsnprintf + 224
4 libgmt.6.4.0.dylib 0x00000001032e2690 GMT_Report + 780
5 supplements.so 0x0000000106abd7ec GMT_backtracker + 1536
6 libgmt.6.4.0.dylib 0x00000001032eb14c GMT_Call_Module + 1332
7 gmt 0x000000010296dd50 main + 948
8 dyld 0x0000000102b4108c start + 520

The strange part is if I pip the coordinates / ages in, backtracker works fine e.g.

echo -37.8153 -31.4005 84.2 | gmt backtracker -ESAM-AFR > RGR_hot_spotted.xy

works, but when I try using a file, e.g.

gmt backtracker $RGR_locations -ESAM-AFR > RGR_hot_spotted.xy

I get the error. I’ve tried multiple different $RGR_location files to see if that was the issue but to no avail. The really strange thing is that it also occurs when I try and add a -M0.5 to backtracker. Even when I pip in coordinates / age like:

echo -37.8153 -31.4005 84.2 | gmt backtracker -ESAM-AFR -M0.5 > RGR_hot_spotted.xy

I will get the same segmentation fault error. Any ideas? Eventually I want to take a dataset of points with ages and backtrack them but using the -M0.5 scaling factor. Many thanks

  • Peter
2

Hi Peter, I cannot reproduce it. I am running 6.4 as you for this test (macOS bundle). Unless there is some junk in your $RGR_locations file of course.

Works fine:
echo -37.8153 -31.4005 84.2 | gmt backtracker -ESAM-AFR > RGR_hot_spotted.xy

echo -37.8153 -31.4005 84.2 > t.txt
gmt backtracker -ESAM-AFR t.txt > RGR_hot_spotted.xy

3

Hi Paul, yes I’m also running 6.4 on macOS. I can’t figure out what might be wrong with my input files since it occurs on all that I try, including running the script above where the lat/lon/age is echoed into a .txt and then ran through backtracker. I wonder if something is getting confused on the back end of my computer?

4

Only backtracker or does psxy also give the same response? Since all the table tools in GMT share the same internal i/o it is hard to understand what is happening. Food for thought:

  1. More than one GMT installation?
  2. does od -c $RGR_locations give odd non-text output at the ends or anywhere.

???

5

I did indeed have an old GMT5.4 installed, but deleting that didn’t help. Anyways, I got a new work computer last week and did a fresh homebrew install of GMT6.5 on there. Unfortunately it’s not working here either, though for a different reason. When I run

gmt backtracker $RGR_dredges -ESAM-AFR -V > ${tempfiles}RGR_backtracked.xy

I get

backtracker [ERROR]: Unable to find GPLATES_ROTATIONS file : /opt/homebrew/Cellar/gmt/6.5.0/share/gmt/Muller2019-Young2019-Cao2020_CombinedRotations.rot.rot

When I go to that file directory, indeed the rotation files are not there, but one folder deeper in ‘/spotter’, so how do I get backtracker to look there instead? Many thanks