Re: ncurses 6.6-20260314 can no longer read xterm_256color extended attributes on redhat 8+ systems

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On Thu, Jul 16, 2026 at 04:19:16PM +0000, Todd Richmond wrote:
> Nurses on Redhat 8 and Alma 9 systems can no longer handle the large exte=
nded
> attributes of TERM such as xterm_256color

Redhat 8 has ncurses 6.1

"xterm-256color"

(no underscore)
=20
> This is proven simply by running =E2=80=9Cinfocmp xterm-256color=E2=80=9D=
 vs "infocmp -x
> xterm-256color=E2=80=9D.  The -x option causes =E2=80=9Cno match in termi=
nal database for
> terminal type=E2=80=9D.  The =E2=80=9Cclear=E2=80=9D command also returns=
 =E2=80=9Cunknown terminal type=E2=80=9D
>=20
> Strace on =E2=80=9Cclear=E2=80=9D shows the terminal file opened+read cor=
rectly but it fails
> during initialization
>=20
> ncurses 6.6-20260301 works correctly so that 2 week window should narrow =
down
> the problem.  No later version up to and including ncurses 6.6-20260711 h=
as a
> fix

sure - the size of the compiled terminal description went past 4096 bytes,
which is what ncurses 6.1 works with.

Mixing old code and new data leads to unexpected results.

(compiling a newer terminfo.src with ncurses 6.1 should produce a warning)
=20
> Here are my configure options, but I=E2=80=99ve tried many variants w/o d=
iff -
> especially trying to remove -disable-widec, enable-relocatable,
> enable-sp-funcs, and with-gpm.  None make a difference.  Ncurses is compi=
led
> with gcc 15 and 16 and all the absolute latest gnu utils - not the OEM
> components
>=20
>=20
>=20
> --disable-db-install --disable-widec --enable-fvisibility --enable-reloca=
table --enable-pc-files --enable-sp-funcs --libdir=3D$dstlibdir --with-cxx-=
shared --with-gpm --with-shared --datadir=3D/usr/share
>=20
>=20
> TIA
>=20

--=20
Thomas E. Dickey <[email protected]>
https://invisible-island.net

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