debug.error

debug.error returns a data frame representing the backwards lineage of (the steps leading up to) the error in the execution, if any.

Each data frame contains the following columns:

• scriptNum The script number the exception is associated with.
• scriptName The name of the script the exception is associated with.
• startLine The line number the exception is associated with.
• code The line of code which threw the exception.

Usage

The function signature for debug.error is:

debug.error(stack.overflow = FALSE)

The parameter for this function is:

• stack.overflow If TRUE, the error message will be searched for on Stack Overflow.

This function may be called only after initialising the debugger using either prov.debug, prov.debug.run, or prov.debug.file. For example:

prov.debug.run("myScript.R")
debug.error()
debug.error(stack.overflow = TRUE)

Usage Examples

Let myScript.R be the following:

x <- 1
x <- a + x

Running this script will result in the following error:

Error in eval(annot, environ, NULL) : object 'a' not found

1. stack.overflow is FALSE

The backwards lineage of the error in the script, if any, is returned.

The result of debug.error() is:

Your Error: Error in eval(annot, environ, NULL): object 'a' not found

Code that led to error message:

  scriptNum scriptName startLine       code
1         1 myScript.R         1     x <- 1
2         1 myScript.R         2 x <- a + x

2. stack.overflow is TRUE

In addition to returning the backwards lineage of the error, the error will also be searched on Stack Overflow.

The result of debug.error(stack.overflow = TRUE) is:

Your Error: Error in eval(annot, environ, NULL): object 'a' not found

Code that led to error message:

  scriptNum scriptName startLine       code
1         1 myScript.R         1     x <- 1
2         1 myScript.R         2 x <- a + x


Results from StackOverflow:
[1] "Object not found error with ddply inside a function"                  
[2] "ggplot object not found error when adding layer with different data"  
[3] "Error in eval(expr, envir, enclos) : object not found"                
[4] "data.table throws \"object not found\" error"                         
[5] "Object not found error when passing model formula to another function"
[6] "Object not found error with ggplot2"                                  

Choose a numeric value that matches your error the best or q to quit: 

An integer between 1 and 6 (inclusive) can be entered, or 'q' to exit the function. If a number between 1 and 6 is chosen, a window will pop up linking to the page on Stack Overflow.

The function will continue to wait for input (not terminate) until 'q' has been given.

Once 'q' has been given, the function will return with the error's backwards lineage.

Code that led to error message:

  scriptNum scriptName startLine       code
1         1 myScript.R         1     x <- 1
2         1 myScript.R         2 x <- a + x