[build2] possible to do something similar to DESTDIR= make install?

[Boris Kolpackov]

Norbert Lange <nolange79 at gmail.com> writes:

> Debian packages are supposed to use "the archives as is from the
> build2 distribution".
> 
> BTW. it would be great if there is a way to list all build2 archives
> (or at least the latest version).

Hm, I am starting to wonder if it's better to go back to using the
build2-toolchain archive. This way we get:

1. All the sources (build2, libbutl) as subdirectories so we should be able
   to setup an out of tree bootstrap and build (but see below).

2. There is the toolchain.sha256 file in:

   https://stage.build2.org/0/   (stage)
   https://download.build2.org/  (release)

   That points to the latest version (the first line is always for the
   build2-toolchain archive; we use it for our build bots).

There is a small issue with using build2-toolchain and having output
directories inside: it is itself a build2 project. We can, however,
"cut it off" by creating configurations for output directories (they
have amalgamation= in their bootstrap.build which cuts off the outer
project). Here are the command lines (you can read more about create
in b(1)):

# Bootstrap.
#
mkdir build2-boot
make -C build2-boot -f ../build2/bootstrap.gmake CXX=g++ -j 8
build2-boot/build2/b-boot --version

# Static build.
#
build2-boot/build2/b-boot create: build2-static/,cxx \
  config.cxx=g++        \
  config.bin.lib=static
build2-boot/build2/b-boot configure: libbutl/@build2-static/libbutl/
build2-boot/build2/b-boot configure: build2/@build2-static/build2/
build2-boot/build2/b-boot build2-static/build2/build2/
build2-static/build2/build2/b --version

# Shared build.
#
build2-static/build2/build2/b create: build2-shared/,cxx \
 config.cxx=g++                  \
 config.cc.coptions=-O3          \
 config.bin.rpath=/usr/local/lib \
 config.install.root=/usr/local  \
 config.install.sudo=sudo
build2-static/build2/build2/b configure: libbutl/@build2-shared/libbutl/
build2-static/build2/build2/b configure: build2/@build2-shared/build2/
build2-static/build2/build2/b build2-shared/
build2-static/build2/build2/b install: build2-shared/

Then cleanup is a matter of deleting the output directories.


> The naming scheme is completely different, look at these:
> 
> ./libboost_filesystem.so.1.62.0
> ./libboost_filesystem.a
> ./libboost_filesystem.so
> 
> ./libbutl.so
> ./libbutl.a
> ./libbutl-0.7.0-a.0.z.so

Ok, a couple of points:

1. Firstly, there was a bug (which is now fixes), the last name should have
   been in this form:

   libbutl-0.7.0-a.0.510bad1358bc443a.so

2. Once you switch to using released versions, it will become much tidier:

   libbutl-0.7.so

3. We are currently using platform-independent library versioning scheme
   by embedding the relevant version part into the library name. There is
   nothing wrong with this approach and there are quite a few libraries
   packaged for Debian that use it (for example, our own ODB runtimes).

   There is provision (but not actual implementation) in build2 to support
   platform-specific library versioning schemes (the semantics is very
   different on each platform). So eventually we will get there.

Boris