主機名：名稱或服務未知

我在安裝 2 個軟體包的過程中遇到了這個錯誤。

root@blackbox:~# apt-get install mpack ssmtp
Reading package lists... Done
Building dependency tree
Reading state information... Done
mpack is already the newest version.
ssmtp is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.
2 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] Y
Setting up ssmtp (2.64-8) ...
hostname: Name or service not known
dpkg: error processing package ssmtp (--configure):
subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of mailutils:
mailutils depends on default-mta | mail-transport-agent; however:
 Package default-mta is not installed.
 Package mail-transport-agent is not installed.
 Package ssmtp which provides mail-transport-agent is not configured yet.

dpkg: error processing package mailutils (--configure):
dependency problems - leaving unconfigured
Errors were encountered while processing:
ssmtp
mailutils
E: Sub-process /usr/bin/dpkg returned an error code (1)
root@blackbox:~#

問題是輸入的值/etc/hostname與/etc/hosts.

這會導致命令hostname --fqdn返回無法解析的主機名，從而導致ssmtp無法安裝。

確保將機器的主機名添加到/etc/hosts.

相關錯誤：

• https://bugs.launchpad.net/ubuntu/+source/ssmtp/+bug/582191
• https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=611302

這些似乎很糟糕：

hostname: Name or service not known
dpkg: error processing package ssmtp (--configure):
subprocess installed post-installation script returned error exit status 1

hostname在腳本中使用postinst（在 Debian 軟體包維護者指南中描述 -連結）失敗。

正如我ssmtp在 2.64-8 (amd64) 版本中檢查提到的包，它有以下腳本：

#!/bin/sh

set -e

if test -L /usr/doc/ssmtp
then
   rm -f /usr/doc/ssmtp 2>/dev/null || true
fi

. /usr/share/debconf/confmodule

db_get ssmtp/root
root="$RET"

db_get ssmtp/mailhub
mailhub="${RET:-mail}"

db_get ssmtp/port
port="$RET"

db_get ssmtp/hostname
hostname="${RET:-`hostname --fqdn`}"

db_get ssmtp/rewritedomain
rewritedomain="$RET"

if test -s /etc/mailname
then
   :
else
   test -n "$hostname" && MailName="$hostname"
   test -n "$rewritedomain" && MailName="$rewritedomain"

   touch /etc/mailname
   chmod 644 /etc/mailname
   echo "$MailName" > /etc/mailname
fi

db_get ssmtp/fromoverride
test "$RET" = "true" && FromOverride=YES

test -d /etc/ssmtp || exit 1

if test -s /etc/ssmtp/ssmtp.conf
then
   if test "$port" = "25" -o -z "$port"
   then
       :
   else
       mailhub=${mailhub}:$port
   fi
   test -z "$FromOverride" && FromOverride=NO

   touch /etc/ssmtp/ssmtp.conf.tmp
   chmod 644 /etc/ssmtp/ssmtp.conf.tmp

   sed "s/^root=.*/root=$root/;s/^mailhub=.*/mailhub=$mailhub/;s/^rewriteDomain=.*/rewriteDomain=$rewritedomain/;s/^hostname=.*/hostname=$hostname/;s/^FromLineOverride=.*/FromLineOverride=$FromOverride/;s/^#FromLineOverride=.*/FromLineOverride=$FromOverride/" /etc/ssmtp/ssmtp.conf > /etc/ssmtp/ssmtp.conf.tmp
   mv -f /etc/ssmtp/ssmtp.conf.tmp /etc/ssmtp/ssmtp.conf
else
   touch /etc/ssmtp/ssmtp.conf
   chmod 644 /etc/ssmtp/ssmtp.conf

   exec 1>/etc/ssmtp/ssmtp.conf

   echo "#"
   echo "# Config file for sSMTP sendmail"
   echo "#"
   echo "# The person who gets all mail for userids < 1000"
   echo "# Make this empty to disable rewriting."
   echo "root=$root"
   echo
   echo "# The place where the mail goes. The actual machine name is required no "
   echo "# MX records are consulted. Commonly mailhosts are named mail.domain.com"
   if test "$port" = "25" -o -z "$port"
   then
       echo "mailhub=$mailhub"
   else
       echo "mailhub=${mailhub}:$port"
   fi
   echo
   echo "# Where will the mail seem to come from?"
   test -z "$rewritedomain" && echo -n "#"
   echo "rewriteDomain=$rewritedomain"
   echo ""
   echo "# The full hostname"
   echo "hostname=$hostname"
   echo
   echo "# Are users allowed to set their own From: address?"
   echo "# YES - Allow the user to specify their own From: address"
   echo "# NO - Use the system generated From: address"
   test -z "$FromOverride" && echo -n "#"
   echo "FromLineOverride=YES"
fi

# Program End
exit 0

最重要的是：

hostname="${RET:-`hostname --fqdn`}"

如前所述，hostname --fqdn失敗了。如果出現以下情況，請檢查：

• 命令存在
• hostname --fqdn返回什麼命令

引用自：https://unix.stackexchange.com/questions/263706