I added a custom build system definition with a file_regex.
When run, the output of the custom build system correctly displays in ST2. Manually navigating to the specified file, line and column in ST2 is correctly the location of the error.
When double clicking on an error in the build system output, while the correct file is displayed, the cursor often jumps to the wrong line and column.
The column appears to be interpreted by ST2 to be a character offset from the start of the line rather than the column index.
In other words, an error in the build system output for "line 122 column 4" when double clicked on will often jump past the specified column to something like line 122, column 16 as the "column 4" of the build output is interpreted by ST2 as "character offset 4" (in this example, jumping over four tab characters.