4.1 does not have support for negative subscripts to indexed arrays (a feature that makepkg depends on).
From the bash CHANGES log list of changes between 4.1-release and 4.2-alpha:
Negative subscripts to indexed arrays, previously errors, now are treated as offsets from the maximum assigned index + 1. Fixes "/usr/bin/makepkg: line 2774: idx: bad array subscript" seen w/ 4.1. Signed-off-by: Aaron Campbell <aaron@monkey.org> --- configure.ac | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/configure.ac b/configure.ac index 359d61b..a8d339c 100644 --- a/configure.ac +++ b/configure.ac @@ -183,18 +183,18 @@ AC_DEFUN([AX_PROG_PERL_VERSION], AX_PROG_PERL_VERSION([5.10.1], [], [AC_MSG_ERROR([perl is too old])]) AS_IF([test "x$BASH_SHELL" = "xfalse"], - AC_MSG_WARN([*** bash >= 4.1.0 is required for pacman scripts]), + AC_MSG_WARN([*** bash >= 4.2.0 is required for pacman scripts]), [bash_version_major=`$BASH_SHELL -c 'echo "${BASH_VERSINFO[[0]]}"'` bash_version_minor=`$BASH_SHELL -c 'echo "${BASH_VERSINFO[[1]]}"'` ok=yes if test "$bash_version_major" -lt 4; then ok=no fi - if test "$bash_version_major" -eq 4 && test "$bash_version_minor" -lt 1; then + if test "$bash_version_major" -eq 4 && test "$bash_version_minor" -lt 2; then ok=no fi if test "$ok" = "no"; then - AC_MSG_ERROR([*** bash >= 4.1.0 is required for pacman scripts]) + AC_MSG_ERROR([*** bash >= 4.2.0 is required for pacman scripts]) fi unset bash_version_major bash_version_minor ok]) -- 2.5.0