add line numbers to errors

[aterjung]

Hi,

thank you for your great work! Sadly, there is a great problem using it for me. Some times, my import stops and did not tell anything about the reason for not importing. Looks like:
Begin data validation The validation is complete., Checked rows: 2822, checked entities: 2822, invalid rows: 4, total errors: 4 Import data validation is complete. Begin import of "catalog_product" with "replace" behavior Checked rows: 2822, checked entities: 5640, invalid rows: 4, total errors: 4, The import was successful. 2822 items imported in 1.2 sec, 2422.3 items / sec (208.5mb used)

But in fact, nothing is imported, as long as these 4 error lines persist. The import has 3000 products, it is a hard pain to find the breaking lines in the import. Is there any way to get some infos whats breaking here?