Пакет festvox_cmu_us_bdl_arctic_hts невозможно установить в текущем Сизифе:

apt> install festvox_cmu_us_bdl_arctic_hts
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.

Since you only requested a single operation it is extremely likely that
the package is simply not installable and a bug report against
that package should be filed.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
  festvox_cmu_us_bdl_arctic_hts: Depends: festival
                                 Depends: festlex_POSLEX
                                 Depends: festlex_CMU
E: Broken packages
apt> install festival festvox_cmu_us_bdl_arctic_hts
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
  festival: Conflicts: festvox_cmu_us_bdl_arctic_hts (< 2.0)
E: Broken packages


Действительно, спек festival недвусмысленно указывает, что некоторые пакеты надо обновить:

# upgrade to 2.0.95
Conflicts: festvox_cmu_us_awb_arctic_hts < 2.0
Conflicts: festvox_cmu_us_bdl_arctic_hts < 2.0
Conflicts: festvox_cmu_us_jmk_arctic_hts < 2.0
Conflicts: festvox_cmu_us_slt_arctic_hts < 2.0


Из этих 4 в Сизифе есть 3:
festvox_cmu_us_awb_arctic_hts   1.96-alt1
festvox_cmu_us_bdl_arctic_hts   1.96-alt1
festvox_cmu_us_jmk_arctic_hts   1.96-alt1