I use this manual
https://github.com/bitcoin/bitcoin/blob/master/doc/gitian-building.md
How can I solve the problem?
Creating build script (var/build-script)
Running build script (log in var/build.log)
./bin/gbuild:21:in `system!': failed to run on-target setarch x86_64 bash -x < var/build-script > var/build.log 2>&1 (RuntimeError)
from ./bin/gbuild:149:in `build_one_configuration'
from ./bin/gbuild:285:in `block (2 levels) in <main>'
from ./bin/gbuild:280:in `each'
from ./bin/gbuild:280:in `block in <main>'
from ./bin/gbuild:278:in `each'
from ./bin/gbuild:278:in `<main>'
tail -f var/build.log
libtool: install: /usr/bin/install -c .libs/libprotoc.a /home/ubuntu/build/bitcoin/depends/work/staging/arm-linux-gnueabihf/native_protobuf/2.6.1-70c104d3b77/home/ubuntu/build/bitcoin/depends/arm-linux-gnueabihf/native/lib/libprotoc.a
libtool: install: strip --strip-debug /home/ubuntu/build/bitcoin/depends/work/staging/arm-linux-gnueabihf/native_protobuf/2.6.1-70c104d3b77/home/ubuntu/build/bitcoin/depends/arm-linux-gnueabihf/native/lib/libprotoc.a
libtool: install: chmod 644 /home/ubuntu/build/bitcoin/depends/work/staging/arm-linux-gnueabihf/native_protobuf/2.6.1-70c104d3b77/home/ubuntu/build/bitcoin/depends/arm-linux-gnueabihf/native/lib/libprotoc.a
libtool: install: ranlib /home/ubuntu/build/bitcoin/depends/work/staging/arm-linux-gnueabihf/native_protobuf/2.6.1-70c104d3b77/home/ubuntu/build/bitcoin/depends/arm-linux-gnueabihf/native/lib/libprotoc.a
libtool: install: warning: remember to run `libtool --finish /home/ubuntu/build/bitcoin/depends/arm-linux-gnueabihf/native/lib'
/bin/mkdir -p '/home/ubuntu/build/bitcoin/depends/work/staging/arm-linux-gnueabihf/native_p