Discussion: Hadrian's defaults

[Herbert Valerio Riedel]

On 2019-03-15 at 13:28:21 -0400, Ben Gamari wrote:

[...]

> We should keep in mind that users and packagers, not GHC developers, are
> the primary audience of GHC's build system. For their sake we should
> strive to keep GHC's build system as close to the usual
> configure/make/make install workflow as possible.

Actually, even as a GHC developer, I strongly prefer the IMO quite
intuitive configure/make phase-separated workflow I've been used to for
over 2 decades. It's deeply ingrained into my muscle memory and my
tooling automatically knows what to do when it discovers a `configure`
script and/or a `GNUmakefile`/`Makefile` file in the filesystem and I'm
not excited to have to adapt all my dev scripts/integrations to make
them Hadrian-aware which is effectively a bespoken build-system used by
exactly one project and starting with a specific version of the project
while the previous ones still require Makefiles.

> In fact, I have at times wondered whether when we switch to Hadrian as
> our primary build system we should ship our source distributions with a
> stub makefile to build and run hadrian, allowing downstreams to treat
> the distribution as a normal autotools-based package.

Definitely, I've been wanting this as well! It's perfectly fine IMO to
have it be a best-effort leaky abstraction. It'd be great if the
following standard invocations kept working, which represents the usage
pattern I use both in packaging scripts as well as in my dev-workflow
scripts.

The less I have to be aware of Hadrian pulling the strings behind the
curtains for my 80% use-cases the better. And if I need to do something
from the remaining 20% of use-cases that's when I'd be willing to invoke
Hadrian directly, as that's also when I'd be doing something
non-standard/non-routine anyway and I'd be consciously paying attention
anyway...


,----
| # an example build.mk with some of the keys I typically set one way or
| # another; just support a flat simple key/value grammar as text-file
| # config input to Hadrian
| 
| cat > mk/build.mk  <<EOF
| #INTEGER_LIBRARY   = integer-simple
| BUILD_DOCBOOK_HTML = NO
| BUILD_DOCBOOK_PDF  = NO
| BUILD_DOCBOOK_PS   = NO
| BUILD_MAN          = NO
| BUILD_PROF_LIBS    = NO
| BUILD_SPHINX_HTML  = NO
| BUILD_SPHINX_PDF   = NO
| DYNAMIC_BY_DEFAULT   = NO
| DYNAMIC_GHC_PROGRAMS = NO
| GhcLibWays         = v dyn p
| HADDOCK_DOCS       = NO
| HSCOLOUR_SRCS      = NO
| LATEX_DOCS         = NO
| V                  = 0
| EOF
|
| ./boot
| ./configure --prefix /opt/ghc/HEAD ...otherflags...
|
| # the usual targets I use
|
| make clean
| make distclean
| make all
| make install
| make sdist
| make binary-dist
`----