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1.2.3 Debugging Scheme code
When debugging large Scheme programs, it is helpful when an error
occurs to be pointed to the precise line in the program where it
was raised. In order to enable source locations to be shown for
errors in Scheme code, LilyPond must be run with the command-line
option -dcompile-scheme-code. Alternatively, writing
#(ly:set-option 'compile-scheme-code) at the top of
the LilyPond file has the same effect.
Furthermore, to obtain even more information about the error, you
may use the -ddebug-eval option, or the code
#(debug-enable 'backtrace) in the file. Under this mode,
when an error occurs, a verbose “backtrace” is displayed,
containing information about all function calls that led to the
problematic spot.
Known issues and warnings
Due to a limitation in the Guile implementation, the -dcompile-scheme-code option currently makes it impossible to compile LilyPond files with more than a few thousand Scheme expressions.