build: Review of depends tree configure flags #16354

While doing depends builds, I noticed that there are many configure flags that weren't recognized by our packages. This leads to things like: #16183. This is most likely caused by either overzealous configure flag adding, or updating depends packages without looking at changes to accepted configure flags.

I propose that we:

1. Prune configure flags from depends that packages don't understand.
2. Add documentation on updating packages (namely that new configure flags should be checked).
3. (stretch-goal) Find out what --without- and --disable- configure flags we can supply to speed up depends builds.

CC @fanquake @theuni

Is there a grep line you could use to find all flags that are not understood in a full (fresh) depends build output?

@MarcoFalke I believe you can grep '\bconfigure\b.\+\bunrecognized options\b' on stderr

Here's a non-extensive list of some of the outstanding unrecognized options::

macOS

make bdb_configured -C depends/
configure: WARNING: unrecognized options: --disable-dependency-tracking
configure: WARNING: If you wanted to set the --build type, don't use --host.
    If a cross compiler is detected then cross compile mode will be used.
configure: WARNING: unrecognized options: --disable-dependency-tracking

PROTOBUF=1 make protobuf_configured -C depends/
configure: WARNING: Impossible to determine how to use pthreads with shared libraries and -nostdlib

debian

make freetype_configured -C depends/
configure: WARNING: unrecognized options: --disable-dependency-tracking

make libxcb_configured -C depends/
configure: WARNING: unrecognized options: --disable-dependency-tracking, --disable-shared, --with-pic
configure: WARNING: xmllint not found; unable to validate against schema.
configure: WARNING: unrecognized options: --disable-dependency-tracking, --disable-shared, --with-pic
-c:2: DeprecationWarning: the imp module is deprecated in favour of importlib; see the module's documentation for alternative uses
Package xorg-macros was not found in the pkg-config search path.
Perhaps you should add the directory containing `xorg-macros.pc'
to the PKG_CONFIG_PATH environment variable
No package 'xorg-macros' found
configure: WARNING: if you wanted to set the --build type, don't use --host.
    If a cross compiler is detected then cross compile mode will be used
Package xorg-macros was not found in the pkg-config search path.
Perhaps you should add the directory containing `xorg-macros.pc'
to the PKG_CONFIG_PATH environment variable
No package 'xorg-macros' found
ar: `u' modifier ignored since `D' is the default (see `U')
libtool: install: warning: remember to run `libtool --finish /bitcoin/depends/x86_64-pc-linux-gnu/lib'

make libXau_configured -C depends/
configure: WARNING: if you wanted to set the --build type, don't use --host.
    If a cross compiler is detected then cross compile mode will be used
Package xorg-macros was not found in the pkg-config search path.
Perhaps you should add the directory containing `xorg-macros.pc'
to the PKG_CONFIG_PATH environment variable
No package 'xorg-macros' found

make xproto_configured -C depends/
Package xorg-macros was not found in the pkg-config search path.
Perhaps you should add the directory containing `xorg-macros.pc'
to the PKG_CONFIG_PATH environment variable
No package 'xorg-macros' found

make xcb_proto_configured -C depends/
configure: WARNING: unrecognized options: --disable-dependency-tracking, --disable-shared, --with-pic
configure: WARNING: xmllint not found; unable to validate against schema.
configure: WARNING: unrecognized options: --disable-dependency-tracking, --disable-shared, --with-pic

HOST=x86_64-apple-darwin14 make native_cctools_configured
configure: WARNING: unrecognized options: --disable-dependency-tracking

Current depends configure warnings:

macOS

make bdb_configured -C depends/
configure: WARNING: If you wanted to set the --build type, don't use --host.
    If a cross compiler is detected then cross compile mode will be used.

Debian

make xcb_proto_configured -C depends/
configure: WARNING: unrecognized options: --disable-shared, --with-pic
configure: WARNING: xmllint not found; unable to validate against schema.

make xproto_configured -C depends/
Package xorg-macros was not found in the pkg-config search path.
Perhaps you should add the directory containing `xorg-macros.pc'
to the PKG_CONFIG_PATH environment variable
No package 'xorg-macros' found

make libXau_configured -C depends/
configure: WARNING: if you wanted to set the --build type, don't use --host.
    If a cross compiler is detected then cross compile mode will be used
Package xorg-macros was not found in the pkg-config search path.
Perhaps you should add the directory containing `xorg-macros.pc'
to the PKG_CONFIG_PATH environment variable
No package 'xorg-macros' found

Yeah so all the xorg things want xorg-macros to be there so it can regenerate or something... Not 100% sure if it's a good idea to include xorg-macros in depends for more visibility into their Makefile generation

For the --build --host thing, this might be the right clue: https://www.gnu.org/savannah-checkouts/gnu/autoconf/manual/autoconf-2.69/html_node/Specifying-Target-Triplets.html#Specifying-Target-Triplets

For historical reasons, whenever you specify --host, be sure to specify --build too

GitHub trying to be smart... :roll_eyes:

@dongcarl Now that #21403 is merged, what would you like todo here?

Sounds like we can close this :-) Thank you @fanquake for all the work!