Exception on Raspberry Pi
lazarus / 1-Linux

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jdp · 2016-04-13 18:33

Hi all. I am new here and this is my first post.
Hope somebody can help or point me in the correct direction.

I am playing around with Lazarus to see it it will do what I need. I
developed a little app on Windows 7 using a MQTT library.

https://github.com/cutec-chris/TMQTTClient

All works 100% I have tested it on Windows 7 and 10 and it runs for
days without any problems. The thing is I need it to run on the
Raspberry Pi. I need a GUI app to manage and plot data.

I moved the project to the Pi and I got it to compile after I had to
comment out some baud rates and force it to use cThreads. It will
connect to the server and run for a while but then at random it will
get a Access Violation error or just disappear. I have added exception
handling in all my code but it seems it is not getting to it.

When I run it in the IDE I will get this error but it seems that is
something to do with the debugger.

exception class 'External: SIGSEGV'

At address 76813FB4


I am running on

Rasbian Jessie
Lazarus version 1.2.4
FPC 2.6.4

I am using the package
laz_synapse
LAZ_MQTT
LCL


Kind Regards.

Jaco.

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ab1jx · 2016-05-04 16:29

SIGSEGV is a segmentation fault, it's a standard unix thing.  Usually
it means you've tried to access memory outside what's allocated to
you, like beyond your original bounds for an array.  Google it.

Stepping through in the debugger should help you find it.  I haven't
debugged Lazarus under unix.  With C you get a core file that helps,
you can jump right to where it crashed with the segfault.

Just setting up on a Pi here.  But fpc/Lazarus from Debian ports is
almost too old to be useful.  I installed fpc, plan to use that to
bootstrap fpc from svn, then add Lazarus from svn.  Even the latest
fpc release won't cross-compile to Android past 5.0, so essentially
any Android made in the last year.

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molly · 2016-05-04 17:08

@jdp

missing cthreads perhaps ?