build log: http://dpaste.com/3JAL7N2FV
rustc -V: rustc 1.64.0 (a55dd71d5 2022-09-19) uname -a:Linux riscv64 5.18.18-gentoo-riscv64 #2 SMP Mon Aug 22 23:24:50 CST 2022 riscv64 GNU/Linux emerge --info: Portage 3.0.37 (python 3.10.7-final-0, !../../var/db/repos/gentoo/profiles/default/linux/riscv/20.0/rv64gc/lp64d/systemd, gcc-12.2.0, glibc-2.35-r10, 5.18.18-gentoo-riscv64 riscv64) ================================================================= System uname: Linux-5.18.18-gentoo-riscv64-riscv64-with-glibc2.35 KiB Mem: 16364304 total, 6156632 free KiB Swap: 0 total, 0 free Head commit of repository gentoo: 5a8c1ff913af1cfcedc611550eb4197aa1dca22c sh bash 5.1_p16-r2 ld GNU ld (Gentoo 2.39 p4) 2.39.0 app-misc/pax-utils: 1.3.5::gentoo app-shells/bash: 5.1_p16-r2::gentoo dev-java/java-config: 2.3.1::gentoo dev-lang/perl: 5.36.0::gentoo dev-lang/python: 3.10.7::gentoo, 3.11.0_rc2::gentoo dev-lang/rust: 1.63.0-r1::gentoo dev-lang/rust-bin: 1.64.0::gentoo dev-util/cmake: 3.24.2::gentoo dev-util/meson: 0.63.2-r1::gentoo sys-apps/baselayout: 2.9::gentoo sys-apps/sandbox: 2.29::gentoo sys-apps/systemd: 251.4::gentoo sys-devel/autoconf: 2.71-r4::gentoo sys-devel/automake: 1.16.5::gentoo sys-devel/binutils: 2.39-r2::gentoo sys-devel/binutils-config: 5.4.1::gentoo sys-devel/gcc: 12.2.0::gentoo sys-devel/gcc-config: 2.6::gentoo sys-devel/libtool: 2.4.7::gentoo sys-devel/llvm: 13.0.1::gentoo sys-devel/make: 4.3::gentoo sys-kernel/linux-headers: 5.19::gentoo (virtual/os-headers) sys-libs/glibc: 2.35-r10::gentoo Repositories: gentoo location: /var/db/repos/gentoo-dev sync-type: git sync-uri: https://github.com/gentoo/gentoo.git priority: -1000 ACCEPT_KEYWORDS="riscv ~riscv" ACCEPT_LICENSE="@FREE" CBUILD="riscv64-unknown-linux-gnu" CFLAGS="-O2 -pipe" CHOST="riscv64-unknown-linux-gnu" CONFIG_PROTECT="/etc /usr/share/gnupg/qualified.txt" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/sandbox.d /etc/terminfo" CXXFLAGS="-O2 -pipe" DISTDIR="/var/cache/distfiles" ENV_UNSET="CARGO_HOME DBUS_SESSION_BUS_ADDRESS DISPLAY GOBIN GOPATH PERL5LIB PERL5OPT PERLPREFIX PERL_CORE PERL_MB_OPT PERL_MM_OPT XAUTHORITY XDG_CACHE_HOME XDG_CONFIG_HOME XDG_DATA_HOME XDG_RUNTIME_DIR XDG_STATE_HOME" FCFLAGS="-O2 -pipe" FEATURES="assume-digests binpkg-docompress binpkg-dostrip binpkg-logs binpkg-multi-instance buildpkg-live config-protect-if-modified distlocks ebuild-locks fixlafiles merge-sync multilib-strict news parallel-fetch preserve-libs protect-owned qa-unresolved-soname-deps sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr" FFLAGS="-O2 -pipe" GENTOO_MIRRORS="https://mirrors.ustc.edu.cn/gentoo/" LANG="C.UTF8" LDFLAGS="-Wl,-O1 -Wl,--as-needed" PKGDIR="/var/cache/binpkgs" PORTAGE_CONFIGROOT="/" 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="/var/tmp" USE="acl bzip2 cli crypt dri fortran gdbm iconv ipv6 libglvnd ncurses nls nptl openmp pam pcre readline riscv seccomp split-usr ssl systemd udev unicode xattr zlib" ADA_TARGET="gnat_2020" 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 sheets words" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock greis isync itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf skytraq superstar2 timing tsip tripmate tnt ublox ubx" INPUT_DEVICES="libinput" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LUA_SINGLE_TARGET="lua5-1" LUA_TARGETS="lua5-1" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php7-4 php8-0" POSTGRES_TARGETS="postgres12 postgres13" PYTHON_SINGLE_TARGET="python3_10" PYTHON_TARGETS="python3_10" RUBY_TARGETS="ruby27" USERLAND="GNU" VIDEO_CARDS="fbdev v4l" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq proto steal rawnat logmark ipmark dhcpmac delude chaos account" Unset: ADDR2LINE, AR, ARFLAGS, AS, ASFLAGS, CC, CCLD, CONFIG_SHELL, CPP, CPPFLAGS, CTARGET, CXX, CXXFILT, ELFEDIT, EMERGE_DEFAULT_OPTS, EXTRA_ECONF, F77FLAGS, FC, GCOV, GPROF, INSTALL_MASK, LC_ALL, LD, LEX, LFLAGS, LIBTOOL, LINGUAS, MAKE, MAKEFLAGS, MAKEOPTS, NM, OBJCOPY, OBJDUMP, PORTAGE_BINHOST, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, RANLIB, READELF, RUSTFLAGS, SHELL, SIZE, STRINGS, STRIP, YACC, YFLAGS
my solution: mask and uninstall dev-lang/rust-bin-1.64.0 dev-lang/rust-bin-1.64.0-r1
please attach the build log, it will be deleted soon from dpaste
also please consider to open a bug at upstream - https://github.com/dtolnay/proc-macro2 - the rust train is not going to stop for you ;)
ftr rust-1.64.0 is seemingly broken on for ~riscv and was dekeyworded, see: https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=ff2e00c46b3