Libguestfs - Oct 2020 - Re: Build failure of libnbd

[Adding libguestfs mailing list]

I reproduced it locally - the difference was installing "gcc-go".
I only had golang-bin installed previously.  With gcc-go installed:

  ../run go install libguestfs.org/libnbd
  write of Go pointer 0xc000016060 to non-Go memory 0x7f5fe8297390
  fatal error: Go pointer stored into non-Go memory

  runtime stack:
  runtime_mstart
  	../../../libgo/runtime/proc.c:593

Notice that these two packages both provide /usr/bin/go, using
alternatives:

  $ rpm -qf /usr/bin/go
  golang-bin-1.15.3-1.fc34.x86_64
  gcc-go-10.2.1-5.fc34.x86_64
  $ ll /usr/bin/go
  lrwxrwxrwx. 1 root root 20 Oct 15 12:46 /usr/bin/go -> /etc/alternatives/go

So the easy fix is to remove gcc-go from your Dockerfile.

However I will take a look at why gcc-go doesn't work, as I guess we
ought to try to support both, or if gcc-go cannot work then we ought
to reject it in ./configure.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-builder quickly builds VMs from scratch
http://libguestfs.org/virt-builder.1.html

On Sat, Oct 17, 2020 at 08:48:40AM +0100, Richard W.M. Jones
wrote:
> [Adding libguestfs mailing list]
> 
> I reproduced it locally - the difference was installing "gcc-go".
> I only had golang-bin installed previously.  With gcc-go installed:
> 
>   ../run go install libguestfs.org/libnbd
>   write of Go pointer 0xc000016060 to non-Go memory 0x7f5fe8297390
>   fatal error: Go pointer stored into non-Go memory
> 
>   runtime stack:
>   runtime_mstart
>   	../../../libgo/runtime/proc.c:593
> 
> Notice that these two packages both provide /usr/bin/go, using
> alternatives:
> 
>   $ rpm -qf /usr/bin/go
>   golang-bin-1.15.3-1.fc34.x86_64
>   gcc-go-10.2.1-5.fc34.x86_64
>   $ ll /usr/bin/go
>   lrwxrwxrwx. 1 root root 20 Oct 15 12:46 /usr/bin/go ->
/etc/alternatives/go
> 
> So the easy fix is to remove gcc-go from your Dockerfile.
> 
> However I will take a look at why gcc-go doesn't work, as I guess we
> ought to try to support both, or if gcc-go cannot work then we ought
> to reject it in ./configure.
nbdkit-golang-plugin also fails to build with gcc-go:

cd examples/disk && \
PKG_CONFIG_PATH="/home/rjones/d/nbdkit/server/local${PKG_CONFIG_PATH:+:$PKG_CONFIG_PATH}"
\
GOPATH="/home/rjones/d/nbdkit/plugins/golang" \
go build -o nbdkit-godisk-plugin.so -buildmode=c-shared
# _/home/rjones/d/nbdkit/plugins/golang/examples/disk
/usr/bin/ld:
/usr/lib/gcc/x86_64-redhat-linux/10/libgolibbegin.a(libgolibbegin_a-go-libmain.o):
undefined reference to symbol 'pthread_create@@GLIBC_2.2.5'
/usr/bin/ld: /usr/lib64/libpthread.so.0: error adding symbols: DSO missing from
command line
collect2: error: ld returned 1 exit status

Even adding -pthread didn't help here.  I guess gcc-go is just broken.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
Fedora Windows cross-compiler. Compile Windows programs, test, and
build Windows installers. Over 100 libraries supported.
http://fedoraproject.org/wiki/MinGW

On Sat, Oct 17, 2020 at 09:00:30AM +0100, Richard W.M. Jones
wrote:
>On Sat, Oct 17, 2020 at 08:48:40AM +0100, Richard W.M. Jones wrote:
>> [Adding libguestfs mailing list]
>>
>> I reproduced it locally - the difference was installing
"gcc-go".
>> I only had golang-bin installed previously.  With gcc-go installed:
>>
>>   ../run go install libguestfs.org/libnbd
>>   write of Go pointer 0xc000016060 to non-Go memory 0x7f5fe8297390
>>   fatal error: Go pointer stored into non-Go memory
>>
>>   runtime stack:
>>   runtime_mstart
>>   	../../../libgo/runtime/proc.c:593
>>
>> Notice that these two packages both provide /usr/bin/go, using
>> alternatives:
>>
>>   $ rpm -qf /usr/bin/go
>>   golang-bin-1.15.3-1.fc34.x86_64
>>   gcc-go-10.2.1-5.fc34.x86_64
>>   $ ll /usr/bin/go
>>   lrwxrwxrwx. 1 root root 20 Oct 15 12:46 /usr/bin/go ->
/etc/alternatives/go
>>
>> So the easy fix is to remove gcc-go from your Dockerfile.
>>
>> However I will take a look at why gcc-go doesn't work, as I guess
we
>> ought to try to support both, or if gcc-go cannot work then we ought
>> to reject it in ./configure.
>
>nbdkit-golang-plugin also fails to build with gcc-go:
>
>cd examples/disk && \
>PKG_CONFIG_PATH="/home/rjones/d/nbdkit/server/local${PKG_CONFIG_PATH:+:$PKG_CONFIG_PATH}"
\
>GOPATH="/home/rjones/d/nbdkit/plugins/golang" \
>go build -o nbdkit-godisk-plugin.so -buildmode=c-shared
># _/home/rjones/d/nbdkit/plugins/golang/examples/disk
>/usr/bin/ld:
/usr/lib/gcc/x86_64-redhat-linux/10/libgolibbegin.a(libgolibbegin_a-go-libmain.o):
undefined reference to symbol 'pthread_create@@GLIBC_2.2.5'
>/usr/bin/ld: /usr/lib64/libpthread.so.0: error adding symbols: DSO missing
from command line
>collect2: error: ld returned 1 exit status
>
>Even adding -pthread didn't help here.  I guess gcc-go is just broken.
>
Could be, thanks a lot for figuring it out, I hope the time is not wasted and it
at least helps someone somewhere... at some point.

The list of packages is something I will have to go through anyway, for not it
is just a list taken from libvirt CI container with bunch of things added for
libnbd.  The ultimate goal with this is to have automatically updated repository
like libnbd-go that looks exactly how golang developers want it so that they can
consume it the usual way and it should also be properly tagged whenever a tag is
updated in the upstream repository.  The fact that there are some checks
shouldn't hurt, right? ;-)
>Rich.
>
>-- 
>Richard Jones, Virtualization Group, Red Hat
http://people.redhat.com/~rjones
>Read my programming and virtualization blog: http://rwmj.wordpress.com
>Fedora Windows cross-compiler. Compile Windows programs, test, and
>build Windows installers. Over 100 libraries supported.
>http://fedoraproject.org/wiki/MinGW