GHDL BUG : --ieee option not accepted yet documented in man page

[Robert Schott]

Hello,

  The ghdl man page lists the following commands and options:
      Basic commands:

       -a     Analysis, i.e. ghdl -a file.vhdl

       -e     Elabortation, i.e. ghdl -e unit_name

       -r     Run: run the simulation, i.e. ghdl -r unit_name

       -s     Syntax-check, i.e. ghdl -s file.vhdl

       --clean
              Clean: remove generated files, i.e. ghdl --clean

       -h, --help
              Help, i.e. ghdl --help

       --version
              Version, i.e. ghdl --version


      Basic options:

       --work=NAME
              Name of the WORK library, i.e.  ghdl -a --work=foo foo.vhdl

       --std=STD
              Which VHDL standard (87|93|93c|00|02),  i.e.  ghdl  -a  --std=87
              old.vhdl

       --ieee=VER
              Which IEEE library (none|standard|synopsys|mentor), i.e. ghdl -a
              --ieee=synopsys broken.vhdl

       --no-vital-checks
              Disable   VITAL   restriction    checking,    i.e.    ghdl    -a
              --no-vital-checks unsupported_vital.vhdl

 yet when trying to use the --ieee option, the following errors occur:
/usr/lib/ghdl/bin/ghdl: unknown option '--ieee=synopsis' for command '-a'
rschott at blizzard:~/ce6301/hw1$ ghdl -e --ieee=synopsis  mpz.vhdl
/usr/lib/ghdl/bin/ghdl: unknown option '--ieee=synopsis' for command '-e'
rschott at blizzard:~/ce6301/hw1$ ghdl -r --ieee=synopsis  mpz.vhdl
/usr/lib/ghdl/bin/ghdl: unknown option '--ieee=synopsis' for command '-r'
rschott at blizzard:~/ce6301/hw1$ ghdl -s --ieee=synopsis  mpz.vhdl
/usr/lib/ghdl/bin/ghdl: unknown option '--ieee=synopsis' for command '-s'

The above
The other described options work as documented.
I can see from running a dpkg-query --listfiles ghdl that the src and
compiled files to support the options are included with the package.
The executable just does not recognize the option.

Thanks,
Robert Schott