I want to check the use of the pthread_mutex_lock function, so I execute the command man pthread_mutex_lock, the result appears No manual entry for pthread_mutex_lock. I checked the information on the Internet and said that there was a No manual entry for pthread_mutex_lock prompt, need to install manpages-posix-dev.
So I'm ready to install manpages-posix-dev（I execute the command: apt-get install manpages-posix-dev）, but E: Unable to locate package manpages-posix-dev prompts me again. Why?I'm using the debian 10 system.
gyz@debian:~$ man pthread_mutex_lock No manual entry for pthread_mutex_lock gyz@debian:~$ sudo apt-get install manpages-posix-dev Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package manpages-posix-dev gyz@debian:~$ lsb_release -a No LSB modules are available. Distributor ID: Debian Description: Debian GNU/Linux 10 (buster) Release: 10 Codename: buster gyz@debian:~$ getconf LONG_BIT 64 gyz@debian:~$ cat /proc/version Linux version 4.19.0-9-amd64 (email@example.com) (gcc version 8.3.0 (Debian 8.3.0-6)) #1 SMP Debian 4.19.118-2+deb10u1 (2020-06-07)