2.4.0-beta-2 possible regression: Float inset stops instant preview functionality in Fedora 37 X86_64

[Eric Barkan]

This (at bottom) is in reply to Jose Matos' first posting of January 18.

Sorry for the confusion, but I haven't been able to figure out how to 
make a normal reply to the list so that the thread structure is 
maintained.  Any help would be appreciated.

Jose's post:

On Tue, 2023-01-17 at 18:06 -0800, Eric Barkan wrote:
> As a long time user of LyX, I want to thank you all for this awesome
> piece of software.  Couldn't live without it!

Thank you. :-)

> I installed lyx-devel-2.4.0~beta2-1 and its dependencies from the
> jamatos copr lyx-devel repository for Fedora 37 X86_64 using dnf. 
> The program starts and functions normally as far as I can tell,
> except for the instant preview problem described below.
> This same system has lyx-2.3.7-1.fc37 also installed and seeming to
> work perfectly.  Specifically, this bug  does NOT occur on the 2.3.7
> installation.

That is the strange element here.

> Bug Description: Inclusion of a float inset in a .lyx file prevents
> instant preview from functioning.  Removal of the float inset
> restores instant preview functionality.  Details of the float seem
> irrelevant; the attached MRE contains an empty float which causes the
> problem, but I've tried non-empty floats too with the same results.
> Both figure floats and table floats have the same effect.
> I've attached two small lyx files as an MRE.  The file preview-test-
> float.lyx exhibits the bug; it contains an empty float inset.  The
> otherwise identical file preview-test-no-float.lyx (with no float
> inset) does not.
> The files contain two short equations.  In the example with the
> float, clicking in and out of the equations does not force preview,
> and nothing else I've tried seems to either.

Running the same version here I see the preview on both files.

What do you get from Help -> About LyX, in the Version tab you have an
option to "Copy Version Info". In my case I have:

Version 2.4.0-beta2
(Sunday, 11 December 2022)

Qt Version (run-time): 5.15.8 on platform xcb
Qt Version (compile-time): 5.15.8
OS Version (run-time): Fedora Linux 37 (KDE Plasma)
Python detected: python3 -tt

Thinking aloud... here we could also output the Python version, for
consistency sake...

> Thanks again for all your hard work.  Looking forward to the final
> release. 

Thank you for the report,
-- 
José Abílio


My reply:

Jose,

Here's my output from "Copy version info":


Version 2.4.0-beta2
(Sunday, December 11, 2022)

Qt Version (run-time): 5.15.8 on platform xcb
Qt Version (compile-time): 5.15.8
OS Version (run-time): Fedora Linux 37 (Thirty Seven)
Python detected: python3 -tt

Python --version gives "Python 3.11.1"

Also, I've tried running beta-2 from a terminal and I find that "Error: 
No DVI or PDF output. latex failed." is printed after each attempt to 
preview by clicking in and out of an equation.