[gentoo-alt] Prefix bootstrap stage3 pinentry fails when host system has FLTK

[Stephen McCamant]

I've been exploring creating a Gentoo Prefix installation on an x86_64
Ubuntu 16.04 machine where I do not have root, as an alternative way
of installing new software. I managed to finish the bootstrap once and
build a number of packages back in January (back then the host OS was
Ubuntu 14.04). But when I tried to re-do this process yesterday, the
bootstrap process failed during the compilation of the pinentry
program in stage3.

It looks like the problem relates to pinentry's configure script
attempting to auto-detect whether the FLTK GUI toolkit is
available. It's installed on my host machine, but not yet inside the
Prefix, so it shouldn't be used. But the pinentry configure script
finds the host's /usr/bin/fltk-config in my PATH and tries to compile
a FLTK version of pinentry; the compilation then fails because the
FLTK headers are not available inside the Prefix. (Presumably linking
would also fail later because the libraries aren't in the Prefix
either.)

A similar problem that affects the cross-compilation of pinentry was
recently reported in https://bugs.gentoo.org/653938 . One of the
patches attached to that bug
(https://bugs.gentoo.org/attachment.cgi?id=528442&action=diff) sounds
like it would be a fix/workaround for the same problem I'm having: it
adds fltk as a USE flag for the package, and then tells configure to
enable/disable FLTK depending on the USE flag. I'm guessing that
during the bootstrap process, Portage would then know that FLTK was
not available and build without it.

Is there a convenient way to test this change, either by rerunning
some commands in my unfinished bootstrap directory, or by redoing the
bootstrap but inserting a patched version of the pinentry ebuild file?

I've pasted below the most relevant excerpts from the stage3 log, and
the output of emerge --info. Let me know if it would also be helpful
to add a comment on the existing bug, or create a new bug perhaps with
even more logs.

 -- Stephen

>>> Emerging (26 of 35) app-crypt/pinentry-1.1.0-r1::gentoo
 * pinentry-1.1.0.tar.bz2 BLAKE2B SHA512 size ;-) ...
     [ ok ]
>>> Unpacking source...
>>> Unpacking pinentry-1.1.0.tar.bz2 to
>>> /scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/var/tmp/portage/app-crypt/pinentry-1.1.0-r1/work
>>> Source unpacked in
>>> /scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/var/tmp/portage/app-crypt/pinentry-1.1.0-r1/work
>>> Preparing source in
>>> /scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/var/tmp/portage/app-crypt/pinentry-1.1.0-r1/work/pinentry-1.1.0 ...
 * Applying pinentry-1.0.0-make-icon-work-under-Plasma-Wayland.patch
   ...
 [ ok ]
 * Applying pinentry-0.8.2-ncurses.patch ...
 [ ok ]
 * Running eautoreconf in
   '/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/var/tmp/portage/app-crypt/pinentry-1.1.0-r1/work/pinentry-1.1.0' ...
 * Running aclocal -I m4 ...
 [ ok ]
 * Running autoconf --force ...
 [ ok ]
 * Running autoheader ...
 [ ok ]
 * Running automake --add-missing --copy --force-missing ...
 [ ok ]
 * Running elibtoolize in: pinentry-1.1.0/
>>> Source prepared.
>>> Configuring source in
>>>
>>>
>>> /scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/var/tmp/portage/app-crypt/pinentry-1.1.0-r1/work/pinentry-1.1.0 ...
 * econf: updating pinentry-1.1.0/build-aux/config.guess with
   /scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/usr/share/gnuconfig/config.guess
 * econf: updating pinentry-1.1.0/build-aux/config.sub with
   /scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/usr/share/gnuconfig/config.sub
./configure
--prefix=/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/usr
--build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--mandir=/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/usr/share/man
--infodir=/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/usr/share/info
--datadir=/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/usr/share
--sysconfdir=/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/etc
--localstatedir=/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/var/lib
--disable-dependency-tracking --disable-silent-rules
--docdir=/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/usr/share/doc/pinentry-1.1.0-r1
--htmldir=/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/usr/share/doc/pinentry-1.1.0-r1/html
--libdir=/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/usr/lib64
--enable-pinentry-tty --without-libcap --disable-pinentry-emacs
--disable-libsecret --disable-pinentry-gnome3 --disable-pinentry-gtk2
--enable-pinentry-curses --enable-fallback-curses
--disable-pinentry-qt
MOC=/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/usr/lib64/qt5/bin/moc
checking for a BSD-compatible
install...
/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/usr/bin/install
-c
checking whether build environment is sane... yes
[...]
checking for fltk-config... /usr/bin/fltk-config
checking for FLTK 1.3... yes
[...]
configure:

        Pinentry v1.1.0 has been configured as follows:

        Revision:    (0)
        Platform:  x86_64-pc-linux-gnu

        Curses Pinentry ..: yes
        TTY Pinentry .....: yes
        Emacs Pinentry ...: no
        GTK+-2 Pinentry ..: no
        GNOME 3 Pinentry .: no
        Qt Pinentry ......: no 
        TQt Pinentry .....: no
        W32 Pinentry .....: no
        FLTK Pinentry ....: yes

        Fallback to Curses: yes
        Emacs integration : yes

        libsecret ........: no

        Default Pinentry .: pinentry-curses

>>> Source configured.
>>> Compiling source in
>>> /scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/var/tmp/portage/app-crypt/pinentry-1.1.0-r1/work/pinentry-1.1.0 ...
make
SHELL=/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/tmp/bin/bash
-j7 
make  all-recursive
[...]
x86_64-pc-linux-gnu-g++ -DHAVE_CONFIG_H -I. -I..
-I/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/usr/include
-I/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/usr/include
 -I/usr/include/cairo -I/usr/include/glib-2.0
 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/pixman-1
 -I/usr/include/freetype2 -I/usr/include/libpng12
 -I/usr/include/freetype2 -I/usr/include/cairo -I/usr/include/glib-2.0
 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/pixman-1
 -I/usr/include/freetype2 -I/usr/include/libpng12
 -fvisibility-inlines-hidden  -D_LARGEFILE_SOURCE
 -D_LARGEFILE64_SOURCE -D_THREAD_SAFE -D_REENTRANT
 -I/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/usr/include/ncursesw -I../secmem -I../pinentry -Wall -std=c++11 -O2 -pipe -O2 -pipe -std=gnu++11 -c -o qualitypasswindow.o qualitypasswindow.cxx
qualitypasswindow.cxx:25:10: fatal error: FL/Fl_Window.H: No such file
or directory
 #include <FL/Fl_Window.H>
          ^~~~~~~~~~~~~~~~
compilation terminated.
make[2]: *** [Makefile:456: qualitypasswindow.o] Error 1
make[2]: *** Waiting for unfinished jobs....
pinwindow.cxx:26:10: fatal error: FL/Fl.H: No such file or directory
 #include <FL/Fl.H>
          ^~~~~~~~~
compilation terminated.
make[2]: *** [Makefile:456: pinwindow.o] Error 1
passwindow.cxx:28:10: fatal error: FL/Fl_Window.H: No such file or
directory
 #include <FL/Fl_Window.H>
          ^~~~~~~~~~~~~~~~
compilation terminated.
make[2]: *** [Makefile:456: passwindow.o] Error 1
main.cxx:50:10: fatal error: FL/Fl.H: No such file or directory
 #include <FL/Fl.H>
          ^~~~~~~~~
compilation terminated.
make[2]: *** [Makefile:456: main.o] Error 1
make[2]: Leaving directory
'/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/var/tmp/portage/app-crypt/pinentry-1.1.0-r1/work/pinentry-1.1.0/fltk'
make[1]: *** [Makefile:474: all-recursive] Error 1
make[1]: Leaving directory
'/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/var/tmp/portage/app-crypt/pinentry-1.1.0-r1/work/pinentry-1.1.0'
make: *** [Makefile:415: all] Error 2
 * ERROR: app-crypt/pinentry-1.1.0-r1::gentoo failed (compile phase):
 *   emake failed
 * 
 * If you need support, post the output of `emerge --info
   '=app-crypt/pinentry-1.1.0-r1::gentoo'`,
 * the complete build log and the output of `emerge -pqv
   '=app-crypt/pinentry-1.1.0-r1::gentoo'`.
 * The complete build log is located at
   '/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/var/tmp/portage/app-crypt/pinentry-1.1.0-r1/temp/build.log'.
 * The ebuild environment file is located at
   '/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/var/tmp/portage/app-crypt/pinentry-1.1.0-r1/temp/environment'.
 * Working directory:
   '/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/var/tmp/portage/app-crypt/pinentry-1.1.0-r1/work/pinentry-1.1.0'
 * S:
   '/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/var/tmp/portage/app-crypt/pinentry-1.1.0-r1/work/pinentry-1.1.0'

>>> Failed to emerge app-crypt/pinentry-1.1.0-r1, Log file:

>>>
>>>  '/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/var/tmp/portage/app-crypt/pinentry-1.1.0-r1/temp/build.log'

Portage 2.3.18-prefix (python 2.7.3-final-0,
default/linux/amd64/17.0/no-multilib/prefix/kernel-3.2+, gcc-7.3.0,
unavailable, 4.13.0-39-generic x86_64)
=================================================================
                         System Settings
=================================================================
System uname: Linux-4.13.0-39-generic-x86_64-with-debian-stretch-sid
KiB Mem:   197991096 total, 133054224 free
KiB Swap:    3905532 total,   3905532 free
Timestamp of repository gentoo: Mon, 07 May 2018 00:45:01 +0000
Head commit of repository gentoo:
6f597edb19270c32954e252b435c75de43578fc4
sh bash 4.4_p19
ld GNU ld (GNU Binutils for Ubuntu) 2.26.1
app-shells/bash:      4.4_p19::gentoo
sys-devel/binutils:   2.30-r2::gentoo
sys-devel/gcc:        7.3.0-r1::gentoo
sys-devel/gcc-config: 1.9.1::gentoo
Repositories:

gentoo
    location:
    /scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/usr/portage
    sync-type: rsync
    sync-uri: rsync://rsync.prefix.bitzolder.nl/gentoo-portage-prefix
    priority: -1000
    sync-rsync-extra-opts: 

ACCEPT_KEYWORDS="amd64 ~amd64 ~amd64-linux"
ACCEPT_LICENSE="* -@EULA"
CBUILD="x86_64-pc-linux-gnu"
CFLAGS="-O2 -pipe -O2 -pipe"
CHOST="x86_64-pc-linux-gnu"
CONFIG_PROTECT="/etc"
CONFIG_PROTECT_MASK="/etc/env.d /etc/gconf /etc/gentoo-release
/etc/terminfo"
CXXFLAGS="-O2 -pipe -O2 -pipe"
DISTDIR="/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/tmp/usr/portage/distfiles"
FCFLAGS="-O2 -pipe"
FEATURES="assume-digests binpkg-logs config-protect-if-modified
distlocks ebuild-locks fixlafiles force-prefix merge-sync
multilib-strict news parallel-fetch preserve-libs protect-owned
sfperms strict unknown-features-warn unmerge-logs unmerge-orphans
unprivileged"
FFLAGS="-O2 -pipe"
GENTOO_MIRRORS="http://distfiles.gentoo.org"
LANG="en_US.UTF-8"
LDFLAGS="-Wl,-O1 -Wl,--as-needed"
MAKEOPTS="-j7"
PKGDIR="/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/tmp/usr/portage/packages"
PORTAGE_CONFIGROOT="/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/tmp/"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times
--omit-dir-times --compress --force --whole-file --delete --stats
--human-readable --timeout=180 --exclude=/distfiles --exclude=/local
--exclude=/packages --exclude=/.git"
PORTAGE_TMPDIR="/scratch/heathrow/mccamant-public/gentoo-prefix-64-may2018/tmp/var/tmp"
USE="acl amd64 berkdb bzip2 cli crypt cxx dri fortran gdbm iconv ipv6
modules ncurses nls nptl openmp pcre prefix readline seccomp ssl tcpd
unicode zlib" ABI_X86="64" ALSA_CARDS="ali5451 als4000 atiixp
atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938
es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio
via82xx via82xx-modem ymfpci" APACHE2_MODULES="authn_core authz_core
socache_shmcb unixd actions alias auth_basic authn_alias authn_anon
authn_dbm authn_default authn_file authz_dbm authz_default
authz_groupfile authz_host authz_owner authz_user autoindex cache cgi
cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter
file_cache filter headers include info log_config logio mem_cache mime
mime_magic negotiation rewrite setenvif speling status unique_id
userdir usertrack vhost_alias" CALLIGRA_FEATURES="karbon plan sheets
stage words" COLLECTD_PLUGINS="df interface irq load memory rrdtool
swap syslog" CPU_FLAGS_X86="mmx mmxext sse sse2" ELIBC="glibc"
GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt
gpsclock isync itrax mtk3301 nmea ntrip navcom oceanserver oldstyle
oncore rtcm104v2 rtcm104v3 sirf skytraq superstar2 timing tsip
tripmate tnt ublox ubx" INPUT_DEVICES="libinput keyboard mouse"
KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216
lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console
presenter-minimizer" OFFICE_IMPLEMENTATION="libreoffice"
PHP_TARGETS="php5-6 php7-0" POSTGRES_TARGETS="postgres9_5"
PYTHON_SINGLE_TARGET="python3_5" PYTHON_TARGETS="python2_7 python3_5"
RUBY_TARGETS="ruby22 ruby23" USERLAND="GNU" VIDEO_CARDS="amdgpu fbdev
intel nouveau radeon radeonsi vesa dummy v4l" XTABLES_ADDONS="quota2
psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy
condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude
chaos account"
Unset:  CC, CPPFLAGS, CTARGET, CXX, EMERGE_DEFAULT_OPTS, INSTALL_MASK,
LC_ALL, LINGUAS, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS,
PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS