As Bug#21513 is now fixed both in Gnulib (which grep uses when configured --with-included-regex) and in Glibc (which grep uses when configured --without-included-regex) I am marking the bug report as done.
- bug#22793: grep -E assertion failure with back references santiagorr
- bug#22793: grep -E assertion failure with back referen... Jim Meyering
- bug#22793: grep -E assertion failure with back ref... Paul Eggert
- bug#22793: grep -E assertion failure with back... arnold
- bug#22793: grep -E assertion failure with ... Paul Eggert
- bug#21513: assertion error in pop_fai... Paul Eggert
- bug#21513: assertion error in pop... Andreas Schwab
- bug#22793: grep -E assertion failure with back referen... Paul Eggert
