As in 2a5fcfae02
and in 3e67e5c992
using /usr/bin/env allows bash to be looked up in PATH
rather than being hard-coded.
As with the previous changes the same arguments apply
- distributions have scripts to rewrite shebangs on installation and
they know what locations to rely on.
- For tests/compilation we should rather rely on the user to have setup
there PATH correctly.
In particular this makes testing from git easier on NixOS where do not provide
/bin/bash to improve compose-ability.
kernel-4.15's if_ether.h has a bug that the header does not provide
'struct ethhdr'. The bug is introduced by
6926e041a8920c8ec27e4e155efa760aa01551fd (4.15-rc8)
and fixed by da360299b6734135a5f66d7db458dcc7801c826a (4.16-rc3).
This makes systemd built with kernel-4.15 headers.
Fixes#12319.
The L2TP_ATTR_UDP_ZERO_CSUM6_{TX,RX} attributes are introduced by
6b649feafe10b293f4bd5a74aca95faf625ae525, which is included in
kernel-3.16. To support older kernel, let's import the header.
Fixes#12300.
Now linux/in.h has better conflict detection with glibc's
netinet/in.h. So, let's import the headers.
Note that our code already have many workarounds for the conflict,
but in this commit does not drop them. Let's do that in the later
commits if this really helps.
