How to get the error messages of sikuli program in my own log message?

Not clear what you are talking about.

It logs if there is an error.
Can I get the error messages in my log using file.write .

I have the same problem - if you find an answer I'd be very interested.

Because Sikuli log messages don't use Python's standard output, I'm not able to redirect them when I subclass sys.stdout.

@EdEd
In fact nearly all messages are produced on the Java level and captured by the IDE to display them in the message area.

Not tested yet:
using
java -jar path-to-sikuli-script.jar path-to-some.sikuli
to run a script from command line leaves the IDE totally aside and may give you a chance to do what you want.

Another possibility might be to use the respective java classes (Debug?) and the methods Sikuli Sorry, cvurr for your own logging.
Running the script from command line, you could pipe stdout to a file.
Since you seem to have already looked into the code: should be rather easy.

@Eva
Sorry, currently no easy way using the IDE.
Might be EdEd has an idea now ;-)

Can we try using trac ini for this process?

@ Eva
????????????????????????

- trac ini
sorry, what is it and what might it have to do with Sikuli?

- for this process?
what process?

Best guess to the origin of the trac ini comment - comes up a lot with logging searches:

http://sikuli.org/wiki/TracIni

java -Xms64M -Xmx512M -jar "%SIKULI_HOME%\sikuli-script.jar" "file.sikuli" 2>&1 > log.txt

Sikuli logs will stored in log.txt. you can use print() in sikuli script to add your own logs.

oops..sorry not read the above comment by RaiMan. He gave this option already

is there a try catch variant where in catch the error can be caught and logged into a .log or .txt file ?