Unable to create static binary because of undefined reference to dbus_*

Question

I get these errors when I try to statically link my Go program that uses Gopacket:

/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/11/../../../x86_64-linux-gnu/libpcap.a(pcap-dbus.o): in function `dbus_write':
(.text+0x103): undefined reference to `dbus_message_demarshal'
/usr/bin/ld: (.text+0x119): undefined reference to `dbus_connection_send'
/usr/bin/ld: (.text+0x122): undefined reference to `dbus_connection_flush'
/usr/bin/ld: (.text+0x12a): undefined reference to `dbus_message_unref'
/usr/bin/ld: (.text+0x178): undefined reference to `dbus_error_free'
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/11/../../../x86_64-linux-gnu/libpcap.a(pcap-dbus.o): in function `dbus_read':
(.text+0x1c3): undefined reference to `dbus_connection_pop_message'
/usr/bin/ld: (.text+0x1e1): undefined reference to `dbus_connection_pop_message'
/usr/bin/ld: (.text+0x1f6): undefined reference to `dbus_connection_read_write'
/usr/bin/ld: (.text+0x262): undefined reference to `dbus_message_is_signal'
/usr/bin/ld: (.text+0x27f): undefined reference to `dbus_message_marshal'
/usr/bin/ld: (.text+0x2e3): undefined reference to `dbus_free'
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/11/../../../x86_64-linux-gnu/libpcap.a(pcap-dbus.o): in function `dbus_cleanup':
(.text+0x350): undefined reference to `dbus_connection_unref'
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/11/../../../x86_64-linux-gnu/libpcap.a(pcap-dbus.o): in function `dbus_activate':
(.text+0x3fa): undefined reference to `dbus_connection_open'
/usr/bin/ld: (.text+0x412): undefined reference to `dbus_bus_register'
...

Indeed these symbols indeed either do not exist /usr/lib/gcc/x86_64-linux-gnu/11/../../../x86_64-linux-gnu/libpcap.a or show up as undefined. For example:

$ readelf -s /usr/lib/gcc/x86_64-linux-gnu/11/../../../x86_64-linux-gnu/libpcap.a | grep dbus_message_marshal
    42: 0000000000000000     0 NOTYPE  GLOBAL DEFAULT  UND dbus_message_marshal

None of these functions are called from my program, but are happening because of the dependency to Gopacket.

I have libpcap installed:

$ apt list --installed|grep pcap

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

libpcap-dev/jammy,now 1.10.1-4build1 amd64 [installed]
libpcap0.8-dev/jammy,now 1.10.1-4build1 amd64 [installed]
libpcap0.8/jammy,now 1.10.1-4build1 amd64 [installed,automatic]

Is there anything else I need? Here's how I compile:

GOOS=linux CGO_ENABLED=1 go build \
    -ldflags "-linkmode external -extldflags \"-static\"" \
    -o bin/myprog \
    -buildvcs=false

If I do not include -ldflags, the program compiles, but it is not statically linked.

I am using Go 1.18.

Answer 1

do not exist /usr/lib/gcc/x86_64-linux-gnu/11/../../../x86_64-linux-gnu/libpcap.a

They are not in libpcap. They are called by that version of libpcap.

You will have to link with all of the libraries reported by pkg-config --libs --static libdpdk in order to statically link that version of libpcap with any program whether it's in Go or not.

Answer 2

It's seems like it is impossible to make a statically linked binary that uses Gopacket.

I updated the build command to use libdbus-1. This got rid of the undefined dbus_* errors:

GOOS=linux CGO_ENABLED=1 CGO_LDFLAGS="-ldbus-1" go build \
    -ldflags "-linkmode external -extldflags \"-static\"" \
    -o bin/app \
    -buildvcs=false

However, I got this error:

/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/11/../../../x86_64-linux-gnu/libdbus-1.a(libdbus_1_la-dbus-sysdeps-unix.o): in function `_dbus_listen_systemd_sockets':
(.text+0x200e): undefined reference to `sd_listen_fds'
/usr/bin/ld: (.text+0x204f): undefined reference to `sd_is_socket'
collect2: error: ld returned 1 exit status

These functions come from libsystemd. I installed libsystemd-dev, but it seems like there is no static library for libsystemd.