Minimum bash versions

4.2

• more robust test suite: completion-display-width 0 in inputrc
• code cleanups: negative array indexes (but not assignments); suspect grep: [${#
• code cleanups: test/[[ -v
• TBD: lastpipe option

Coverage in our test Docker images:

• centos7

4.2 as the minimum would mean dropping support for the following LTS OS versions that have 4.1:

• CentOS 6 etc, EoL 2020-11-30

4.3

• code cleanups, major niceties: namerefs
• code cleanups: negative array index assignments, unsetting; suspect grep: [${#
• code cleanups: no longer need some array nounset defense like in (($[#COMPREPLY[@]})) && COMPREPLY=("${COMPREPLY[@]/%/ }")

Coverage in our test Docker images:

• ubuntu14

4.3 as the minimum would mean dropping support for the following LTS OS versions that have 4.2:

• RHEL and CentOS 7, EoL 2024-06-30 (ELS 2026-06-30)

4.4

• code cleanups: parameter transformations (e.g. ${foo@Q})

Coverage in our test Docker images:

• (none as of 2025-12)

Will likely skip this directly to 5.0 though, as there were LTS versions with later EoL than any of these already dropped along with dropping 4.3 (see above).

4.4 as the minimum would mean dropping support for the following LTS OS versions that have 4.3:

• Debian 8, EoL 2020-06-30
• Ubuntu 14.04, EoL 2024-04
• Ubuntu 16.04, EoL 2021-04-02/2021-04-02/2026-04-02 (standard/ESM)

5.0

TBD

Coverage in our test Docker images:

• debian10

5.0 as the minimum would mean dropping support for the following LTS OS versions that have 4.4:

• RHEL 8 and derivatives, EoL 2024-05-31/2029-05-31/2032-05-31 (full/maint/extended)
• Debian 9, EoL 2022-06-30
• Ubuntu 18.04, EoL 2023-05-31/2028-04-01 (standard/ESM)

5.1

TBD

Coverage in our test Docker images:

• (none as of 2025-12)

5.1 as the minimum would mean dropping support for the following LTS OS versions that have 5.0:

• Debian 10, EoL 2024-06-30
• Ubuntu 20.04, EoL 2022-10-01/2025-05-31/2030-04-02 (standard/security/ESM)

5.2

TBD

Coverage in our test Docker images:

• (none as of 2025-12)

5.2 as the minimum would mean dropping support for the following LTS OS versions that have 5.1:

• Debian 11, EoL 2026-08-31
• RHEL 9 and derivatives, EoL 2027-05-31/2032-05-31/2035-05-31 (full/maint/extended)
• Ubuntu 22.04, EoL 2024-09-30/2027-04-01/2032-04-09 (standard/security/ESM)

5.3

• 5.3 implements funsubs (${ ...; }) and valsubs (${| ...; }). In particular, we can directly call our helper functions that return results in RETRY.
• 5.3 fixes the Bash 4.3..5.2 bug with trap INT inside completion functions (see #739 (comment), and #827 (comment)), so we can implement finalize hooks (#739).
• 5.3 implements compopt -o fullquote.
• 5.3 has a bug in quoting inside quotations (#1435)

Coverage in our test Docker images:

• alpine (as of 2025-12)
• fedoradev (as of 2025-12)

5.3 as the minimum would mean dropping support for the following LTS OS versions that have 5.2:

• Debian 12 (EoL/editions TBD)
• RHEL 10 and derivatives (EoL/editions TBD)
• Ubuntu 24.04 (EoL/editions TBD)