Unable to build or insufficient instructions to build #21132

According to the build instructions for *nix the first step is to execute a bash script, but this fails with the following error. There are missing steps in the documentation to get a fresh ubuntu box building the exchange software. This is on OS "Ubuntu 20.04.1 LTS" with gcc version "gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0"

root@058f87446885:/bitcoin# ./autogen.sh Makefile.am:8: error: Libtool library used but 'LIBTOOL' is undefined Makefile.am:8: The usual way to define 'LIBTOOL' is to add 'LT_INIT' Makefile.am:8: to 'configure.ac' and run 'aclocal' and 'autoconf' again. Makefile.am:8: If 'LT_INIT' is in 'configure.ac', make sure Makefile.am:8: its definition is in aclocal's search path. /usr/share/automake-1.16/am/depend2.am: error: am__fastdepCXX does not appear in AM_CONDITIONAL /usr/share/automake-1.16/am/depend2.am: The usual way to define 'am__fastdepCXX' is to add 'AC_PROG_CXX'
/usr/share/automake-1.16/am/depend2.am: to 'configure.ac' and run 'aclocal' and 'autoconf' again /usr/share/automake-1.16/am/depend2.am: error: AMDEP does not appear in AM_CONDITIONAL /usr/share/automake-1.16/am/depend2.am: The usual way to define 'AMDEP' is to add one of the compiler tests
/usr/share/automake-1.16/am/depend2.am: AC_PROG_CC, AC_PROG_CXX, AC_PROG_OBJC, AC_PROG_OBJCXX, /usr/share/automake-1.16/am/depend2.am: AM_PROG_AS, AM_PROG_GCJ, AM_PROG_UPC /usr/share/automake-1.16/am/depend2.am: to 'configure.ac' and run 'aclocal' and 'autoconf' again Makefile.am: error: C++ source seen but 'CXX' is undefined Makefile.am: The usual way to define 'CXX' is to add 'AC_PROG_CXX' Makefile.am: to 'configure.ac' and run 'autoconf' again.

My guess is that you haven't installed all of the dependencies listed in the build doc. I can create the same output as you're seeing, in a new Ubuntu Focal Docker container, if all I've apt installed is git & autoconf:

root@7d9c01515d89:/bitcoin# ./autogen.sh
configure.ac:28: installing 'build-aux/install-sh'
configure.ac:28: installing 'build-aux/missing'
Makefile.am:8: error: Libtool library used but 'LIBTOOL' is undefined
Makefile.am:8:   The usual way to define 'LIBTOOL' is to add 'LT_INIT'
Makefile.am:8:   to 'configure.ac' and run 'aclocal' and 'autoconf' again.
Makefile.am:8:   If 'LT_INIT' is in 'configure.ac', make sure
Makefile.am:8:   its definition is in aclocal's search path.
Makefile.am: installing 'build-aux/depcomp'
/usr/share/automake-1.16/am/depend2.am: error: am__fastdepCXX does not appear in AM_CONDITIONAL
/usr/share/automake-1.16/am/depend2.am:   The usual way to define 'am__fastdepCXX' is to add 'AC_PROG_CXX'
/usr/share/automake-1.16/am/depend2.am:   to 'configure.ac' and run 'aclocal' and 'autoconf' again
/usr/share/automake-1.16/am/depend2.am: error: AMDEP does not appear in AM_CONDITIONAL
/usr/share/automake-1.16/am/depend2.am:   The usual way to define 'AMDEP' is to add one of the compiler tests
/usr/share/automake-1.16/am/depend2.am:     AC_PROG_CC, AC_PROG_CXX, AC_PROG_OBJC, AC_PROG_OBJCXX,
/usr/share/automake-1.16/am/depend2.am:     AM_PROG_AS, AM_PROG_GCJ, AM_PROG_UPC
/usr/share/automake-1.16/am/depend2.am:   to 'configure.ac' and run 'aclocal' and 'autoconf' again
Makefile.am: error: C++ source seen but 'CXX' is undefined
Makefile.am:   The usual way to define 'CXX' is to add 'AC_PROG_CXX'
Makefile.am:   to 'configure.ac' and run 'autoconf' again.
parallel-tests: installing 'build-aux/test-driver'
autoreconf: automake failed with exit status: 1

Installing all of the build dependencies will likely fix your issue:

apt-get install build-essential libtool autotools-dev automake pkg-config bsdmainutils python3

That certainly got me a bit closer. Next up executing "./configure"

leads to

"configure: error: libdb_cxx headers missing, Bitcoin Core requires this library for BDB wallet support (--without-bdb to disable BDB wallet support)"

I ran "./configure" right after running "./autogen.sh" without error.

Well if you need BDB wallet support, you should be following the instructions in the same build-unix documentation to install bdb. If you don't need it, pass --without-bdb.

Interesting. After running "./contrib/install_db4.sh pwd" I get the same error after configuring the make target "./configure"

You'll need to follow the instructions that were printed once you ran the install_db4.sh script

Alternatively install libdb++-dev and pass --with-incompatible-bdb. See https://github.com/bitcoin/bitcoin/blob/master/doc/build-unix.md#dependency-build-instructions

Here is a guide that may be helpful:

https://jonatack.github.io/articles/how-to-compile-bitcoin-core-and-run-the-tests