ping6 is now deprecated, make fails

[SanskritFritz]

checking for ping6... no
configure: error: cannot find required executable, bailing out`

The reason why this happens is that the latest iputils package has removed the ping6 executable since the ping executable now supports both ipv4 and ipv6 (ping accepts -4 or -6 flag).
I was able to work around this by symlinking ping6 to ping:

ln -s /usr/bin/ping /usr/bin/ping6

I'm not sure if this has any negative consequences, but it seems to be working fine at the moment.

[ktsaou]

Hm... interestingly the old ping versions do not support the parameters -4 and -6.

@philwhineray any ideas how to fix this?

ping6 is only used by link-balancer and an example config of vnetbuild.

[ktsaou]

@SanskritFritz can you check if the newly linked ping6 behaves like ping -6?

[SanskritFritz]

I can't, sorry, I have IPv6 disabled here.

[davidscholberg]

I've setup this workaround and can test the behavior of the ping6 symlink:

# which ping6
/usr/bin/ping6
# ls -l /usr/bin/ping6 
lrwxrwxrwx 1 root root 13 Mar 12 00:40 /usr/bin/ping6 -> /usr/bin/ping
# ping6 -c 4 ::1
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.050 ms
64 bytes from ::1: icmp_seq=2 ttl=64 time=0.031 ms
64 bytes from ::1: icmp_seq=3 ttl=64 time=0.034 ms
64 bytes from ::1: icmp_seq=4 ttl=64 time=0.038 ms

--- ::1 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 2998ms
rtt min/avg/max/mdev = 0.031/0.038/0.050/0.008 ms

Seems to be working fine, although I'm not sure if there's some edge case that wouldn't work. Let me know if I should test something else.

[philwhineray]

Thanks @davidscholberg that looks fine for a workaround. Could you possibly confirm the exit status of a ping -6 -c 1 ::1 is 0 for me? That will be the most obvious test in a solution but I don't have a suitable version of ping.

@ktsaou this should not be too hard to handle in the configure script - that is what it is there for and we have the notion of commands which do/don't take parameters already. What makes it a bit trickier is the need to provide a variable to skip the checks which some distros need to enable cross-compilation.

@SanskritFritz your workaround looks fine. Although if you are not using IPv6 and building just for you, you can run configure with --disable-ipv6 to remove the dependency. Or, as Costa says, really only link-balancer uses it, so --disable-link-balancer. If you are packaging you need an update to the configure script.

I will try to find some time for this in today if I can, it will only affect more users in future.

[davidscholberg]

@philwhineray

# ping -6 -c 1 ::1
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.071 ms

--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.071/0.071/0.071/0.000 ms
# echo $?
0

[philwhineray]

Great. With any luck the change I just pushed will work for everyone and not need a symlink workaround. @SanskritFritz if it tests out OK for you, could you close the ticket and it will be part of the next release.

[SanskritFritz]

Thanks guys, git head builds fine here, I close the ticket. Waiting for a new release.

[SanskritFritz]

Hello, the new release reintroduced this problem for me. I can't push out a new package due to this:

checking for ping6... no
configure: error: cannot find required executable, bailing out

Tried to build git master head too, same problem. Please look into this.

UPDATE: Hold on, I tried to build 3.1.6 just to check, and it fails too with the same error. I'm on a new archlinux, it is possible that previously I still had a ping6 symlink.

[philwhineray]

If you have IPv6 disabled, you probably want the --disable-ipv6 when configuring?

Or, if you are building a separate package, you might want to treat it as if you are cross-compiling. Specifying:

PING6="/bin/ping -6" ./configure should do what you want then, I think.

[SanskritFritz]

Thank you, this way it works perfectly.