@Peter-Harrald Hi Peter, sorry for the late response. I was still trying to duplicate the problem and then you mentioned it was fixed. My best guess is that one of the apache configuration files wasn't setup properly. Re-installing the package is like the software version of "turning it off and on again", lol.
That Segmentation fault is an opkg bug - see also here.
Sorry I don't know why opkg install apache isn't working now. :-(
Here you are an alternative method:
Download that package to some directory - for example with wget <package.ipk>
Within that directory run the command opkg install <package.ipk>
root@Omega-5BE1:~# wget https://downloads.lede-project.org/releases/packages-17.01/mipsel_24kc/packages/apache_2.4.25-1_mipsel_24kc.ipk
--2017-10-15 10:30:10-- https://downloads.lede-project.org/releases/packages-17.01/mipsel_24kc/packages/apache_2.4.25-1_mipsel_24kc.ipk
Resolving downloads.lede-project.org... 18.104.22.168, 2a01:4f8:202:43ea::3
Connecting to downloads.lede-project.org|22.214.171.124|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 731110 (714K) [application/octet-stream]
Saving to: 'apache_2.4.25-1_mipsel_24kc.ipk'
apache_2.4.25-1_mipsel_24kc.ipk 100%[==============================================================>] 713.97K 99.9KB/s in 7.1s
2017-10-15 10:30:17 (101 KB/s) - 'apache_2.4.25-1_mipsel_24kc.ipk' saved [731110/731110]
root@Omega-5BE1:~# opkg install apache_2.4.25-1_mipsel_24kc.ipk
Installing apache (2.4.25-1) to root...
Installing libapr (1.6.2-1) to root...
Installing libuuid (2.29.2-1) to root...
Installing libaprutil (1.6.0-1) to root...
Installing unixodbc (2.3.4-5) to root...
Installing libltdl (2.4-2) to root...
rm: can't remove '/usr/sbin/httpd': No such file or directory
You should take a look in the initscripts, busybox's httpd
uses some parameters which are maybe unsupported by apache.
cat: can't open '/etc/odbcinst.ini.d/*.ini': No such file or directory
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