Dear Maintainer,

*** Reporter, please consider answering these questions, where appropriate ***

   * What led up to the situation?

I have a fits file which has a linear WCS, not a sky image. It loads fine as an
image, but the panel display the various coordinates has an issue.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?

move the mouse and see what coordinates are.

   * What was the outcome of this action?

it displays %1.8G for X, Y and Z coordinates.

   * What outcome did you expect instead?

I expected the values, as contracted via the CRPIX,CRVAL,CDELT values in the
header.
I should add the original ds9 from SAO (the large single executable) works
fine, this scripting version calling wish is the one with the problem.
I used sao V8.1 for both the ubuntu 20.04LTS and the one I had downloaded a
while back from SAO.

I have a fits file that exemplifies this, which hopefully I can attach in some
next menu.   If not, here's my personal URL (the file will be 48kB)

https://www.astro.umd.edu/~teuben/data/NGC2347.rvos.fits

Hi Peter, William,

thank you for the detailed report, and for the sample file in the Debian
bug report. The effect also happens with the (debianized) version 8.3b1
which is in Debian Experimental. I don't think this directly connected
to WCS: The output we see here is

     %1.8G

which looks much like outputting a format string instead itself instead
of the formatted string (see attached image). When one changes the
setting for "Precision --> Coordinates --> Linear" from 8 to 5, the
output changes to "%1.5G", which shows that it is really the format
string, built from the precision setting. However, I still was unable to
find the place in the code where the format is used to print the output.

William, can I ask you to point me to that location in the source? I
promise that I will do the rest of debugging myself :-)

Best

Ole