Downgrading xorg-server to 1.19.5-r2 restores the mouse in dosbox. I have only one DOS game to try with, but it probably is a dosbox issue with new xorg-server. Also, I tried evdev instead of libinput and it did not fix the problem. Did not try with legacy mouse driver, yet. emerge --info Portage 2.3.40 (python 3.6.5-final-0, default/linux/amd64/17.1/no-multilib, gcc-8.1.0, glibc-2.27-r4, 4.16.13-gentoo x86_64) ================================================================= System uname: Linux-4.16.13-gentoo-x86_64-Intel-R-_Core-TM-_i7-7700K_CPU_@_4.20GHz-with-gentoo-2.6 KiB Mem: 7829364 total, 3266968 free KiB Swap: 2097148 total, 2097148 free Timestamp of repository gentoo: Thu, 14 Jun 2018 09:46:10 +0000 sh bash 4.4_p23 ld GNU gold (Gentoo 2.30 p3 2.30.0) 1.15 distcc 3.2rc1 x86_64-pc-linux-gnu [disabled] ccache version 3.3.4 [disabled] app-shells/bash: 4.4_p23::gentoo dev-java/java-config: 2.2.0-r4::gentoo dev-lang/perl: 5.26.2::gentoo dev-lang/python: 2.7.14-r2::gentoo, 3.6.5-r1::gentoo dev-util/ccache: 3.3.4-r1::gentoo dev-util/cmake: 3.11.3::gentoo dev-util/pkgconfig: 0.29.2::gentoo sys-apps/baselayout: 2.6::gentoo sys-apps/openrc: 0.36::gentoo sys-apps/sandbox: 2.13::gentoo sys-devel/autoconf: 2.13::gentoo, 2.69-r4::gentoo sys-devel/automake: 1.11.6-r3::gentoo, 1.13.4-r2::gentoo, 1.16.1-r1::gentoo sys-devel/binutils: 2.30-r3::gentoo sys-devel/gcc: 7.3.0-r3::gentoo, 8.1.0-r3::gentoo sys-devel/gcc-config: 1.9.1::gentoo sys-devel/libtool: 2.4.6-r5::gentoo sys-devel/make: 4.2.1-r3::gentoo sys-kernel/linux-headers: 4.16-r1::gentoo (virtual/os-headers) sys-libs/glibc: 2.27-r4::gentoo Repositories: gentoo location: /usr/portage sync-type: rsync sync-uri: rsync://rsync.gentoo.org/gentoo-portage priority: -1000 sync-rsync-verify-jobs: 1 sync-rsync-verify-metamanifest: no sync-rsync-extra-opts: sync-rsync-verify-max-age: 24 local location: /usr/local/overlay masters: gentoo priority: 0 bar location: /var/lib/layman/bar masters: gentoo priority: 50 deadbeef-overlay location: /var/lib/layman/deadbeef-overlay masters: gentoo priority: 50 Installed sets: @avidemux, @deadbeef, @smartcard ACCEPT_KEYWORDS="amd64 ~amd64" ACCEPT_LICENSE="*" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-march=native -O2 -fgraphite-identity -floop-interchange -floop-strip-mine -floop-block" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/lib64/libreoffice/program/sofficerc /usr/share/gnupg/qualified.txt" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/dconf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo" CXXFLAGS="-march=native -O2 -fgraphite-identity -floop-interchange -floop-strip-mine -floop-block" DISTDIR="/mnt/turtle/gentoo_dist" EMERGE_DEFAULT_OPTS="--fail-clean=y" ENV_UNSET="DBUS_SESSION_BUS_ADDRESS DISPLAY PERL5LIB PERL5OPT PERLPREFIX PERL_CORE PERL_MB_OPT PERL_MM_OPT XAUTHORITY XDG_CACHE_HOME XDG_CONFIG_HOME XDG_DATA_HOME XDG_RUNTIME_DIR" FCFLAGS="-O2 -pipe" FEATURES="assume-digests binpkg-logs config-protect-if-modified distlocks ebuild-locks fail-clean fixlafiles merge-sync multilib-strict news noinfo parallel-fetch preserve-libs protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr" FFLAGS="-O2 -pipe" GENTOO_MIRRORS="http://distfiles.gentoo.org" INSTALL_MASK="/usr/lib/systemd /etc/systemd *.la" LANG="en_US.utf8" LDFLAGS="-Wl,-O1 -Wl,--as-needed" LINGUAS="en_US en" MAKEOPTS="-j5 -l6" PKGDIR="/home/packages" 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="X aac acpi alsa amd64 apng berkdb bzip2 cairo cli cups cxx dbus dga dri dri3 exif fdk ffmpeg flac fontconfig fortran gdbm gif glamor gold gtk3 gudev hwdb iconv icu id3tag imagemagick infinality ipv6 jbig jpeg ladspa lcms libass libsamplerate libtirpc linguas_en mad matroska mikmod mmx mmxext mng modules mp3 mp4 ncurses nfs nptl nsplugin ogg opengl openmp opus pcre pdf pie png readline rtmp sdl seccomp secure-delete sndfile sox spell sse sse2 sse3 sse4_1 ssl svg theora thunar tiff timidity truetype udev unicode usb v4l vaapi vdpau vorbis wavpack x265 xattr xcomposite xft xinerama xv zlib" ABI_X86="64" 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="aes avx avx2 fma3 f16c mmx mmxext popcnt sse sse2 sse3 sse4_1 sse4_2 ssse3" 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" GRUB_PLATFORMS="pc" INPUT_DEVICES="libinput" KERNEL="linux" L10N="en_US en" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LLVM_TARGETS="X86" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php5-6 php7-0" POSTGRES_TARGETS="postgres9_5 postgres10" PYTHON_SINGLE_TARGET="python3_6" PYTHON_TARGETS="python2_7 python3_6" QEMU_SOFTMMU_TARGETS="i386 x86_64" QEMU_USER_TARGETS="i386 x86_64" RUBY_TARGETS="ruby24 ruby25" SANE_BACKENDS="net" USERLAND="GNU" VIDEO_CARDS="intel i965" 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, LC_ALL, PORTAGE_BINHOST, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS
I am not alone, Debian and Arch users have filed a bug with same issue.
Dosbox team is working on it. Quote: We are working on trying to figure out what goes wrong and how to fix it without breaking it on older Xorg versions. It's related to locking the mouse in a window. Xorg-new behaves differently then. (but still looking for exact difference)
Is there an upstream bug somewhere?
Not that I'm aware of, I emailed them and they responded with promise to work on it. No timelines given.
Try to migrate to "evdev". A system had a the same issue like this described here https://bugs.gentoo.org/670276 The solution has been to migrate to evdev in /etc/portage/make.conf old INPUT_DEVICES="mouse keyboard" new INPUT_DEVICES="evdev"
It is fixed in games-emulation/dosbox-9999. Thanks go to Dosbox team. :)
Thanks for the update. Looks like this was fixed by https://sourceforge.net/p/dosbox/code-0/4177/