go-appimage does NOT follow AppImage spec recommendation nor FHS regarding /usr prefix

[brunvonlope]

The draft spec (https://github.com/AppImage/AppImageSpec/blob/master/draft.md#the-payload-application) says:

It is RECOMMENDED that the payload application and its dependencies are located in a $PREFIX directory tree inside the AppDir with $PREFIX commonly being ./usr/; it is RECOMMENDED that the $PREFIX directory tree inside the AppDir follows the File System Hierarchy conventions for /usr

However, using go-appimage for deployment makes a .appimage with some deps outside the /usr dir (so in AppDir), but others are deployed to inside /usr dir as expected. This inconsistency causes problems:

In GIMP .appimage script (due to babl and GEGL and to conform to the best practices of the spec), we force move deps to inside /usr prefix after -s deploy: https://gitlab.gnome.org/GNOME/gimp/-/blob/2aaeb55ac0293e8c64b12d82e77dbe14bbfef2ff/build/linux/appimage/2_bundle-gimp-appimage.sh#L299, but this corrupts the RPATH of the deps that we needed to force move.

[probonopd]

Thanks @brunvonlope.

The files which are not in ./usr, where are they coming from on the build system? Which files are these?

[brunvonlope]

They are coming from the system prefix. They are libraries and some dirs like gconv

[probonopd]

Can you please list the paths of the affected files? Thanks.

[brunvonlope]

AppDir/lib/arch_triplet have:

gconv/
gdk-pixbuf-2.0/
gtk-3.0/
libICE.so.6
libIex-3_1.so.30
libIlmThread-3_1.so.30
libImath-3_1.so.29
libLerc.so.4
libOpenEXR-3_1.so.30
libSM.so.6
libX11.so.6
libXau.so.6
libXcomposite.so.1
libXcursor.so.1
libXdamage.so.1
libXdmcp.so.6
libXext.so.6
libXfixes.so.3
libXi.so.6
libXinerama.so.1
libXmu.so.6
libXpm.so.4
libXrandr.so.2
libXrender.so.1
libXt.so.6
libaa.so.1
libacl.so.1
libamd.so.2
libaom.so.3
libappstream-glib.so.8
libarchive.so.13
libatk-1.0.so.0
libatk-bridge-2.0.so.0
libatspi.so.0
libavahi-client.so.3
libavahi-common.so.3
libblas.so.3
libblkid.so.1
libbluray.so.2
libbrotlicommon.so.1
libbrotlidec.so.1
libbrotlienc.so.1
libbsd.so.0
libbz2.so.1.0
libc.so.6
libcairo-gobject.so.2
libcairo.so.2
libcamd.so.2
libcanberra-gtk3.so.0
libcanberra.so.0
libcap.so.2
libccolamd.so.2
libcfitsio.so.10
libcholmod.so.3
libcolamd.so.2
libcolord.so.2
libcom_err.so.2
libcrypt.so.1
libcrypto.so.3
libcups.so.2
libcurl-gnutls.so.4
libdatrie.so.1
libdav1d.so.6
libdb-5.3.so
libdbus-1.so.3
libde265.so.0
libdeflate.so.0
libdl.so.2
libepoxy.so.0
libexiv2.so.27
libexpat.so.1
libexslt.so.0
libffi.so.8
libfontconfig.so.1
libfreetype.so.6
libfribidi.so.0
libgcc_s.so.1
libgck-1.so.0
libgcr-base-3.so.1
libgcrypt.so.20
libgdk-3.so.0
libgdk_pixbuf-2.0.so.0
libgexiv2.so.2
libgfortran.so.5
libgio-2.0.so.0
libgirepository-1.0.so.1
libgjs.so.0
libglib-2.0.so.0
libgmodule-2.0.so.0
libgmp.so.10
libgnomekbd.so.8
libgnomekbdui.so.8
libgnutls.so.30
libgobject-2.0.so.0
libgomp.so.1
libgpg-error.so.0
libgpm.so.2
libgraphite2.so.3
libgs.so.10
libgssapi_krb5.so.2
libgtk-3.so.0
libgudev-1.0.so.0
libharfbuzz.so.0
libheif.so.1
libhogweed.so.6
libhwy.so.1
libicudata.so.72
libicuuc.so.72
libidn.so.12
libidn2.so.0
libijs-0.35.so
libjbig.so.0
libjbig2dec.so.0
libjpeg.so.62
libjson-c.so.5
libjson-glib-1.0.so.0
libjxl.so.0.7
libjxl_threads.so.0.7
libk5crypto.so.3
libkeyutils.so.1
libkrb5.so.3
libkrb5support.so.0
liblapack.so.3
liblber-2.5.so.0
liblcms2.so.2
libldap-2.5.so.0
libltdl.so.7
liblz4.so.1
liblzma.so.5
libm.so.6
libmaxflow.so.0
libmd.so.0
libmetis.so.5
libmng.so.1
libmount.so.1
libmozjs-102.so.0
libmypaint-1.5.so.1
libncurses.so.6
libncursesw.so.6
libnettle.so.8
libnghttp2.so.14
libnsl.so.2
libnspr4.so
libnss3.so
libnssutil3.so
libnuma.so.1
libogg.so.0
libopenjp2.so.7
libp11-kit.so.0
libpanelw.so.6
libpango-1.0.so.0
libpangocairo-1.0.so.0
libpangoft2-1.0.so.0
libpaper.so.1
libpcre2-8.so.0
libpixman-1.so.0
libplc4.so
libplds4.so
libpng16.so.16
libpoppler-glib.so.8
libpoppler.so.126
libproxy.so.1
libpsl.so.5
libpthread.so.0
libquadmath.so.0
libraw.so.20
libreadline.so.8
libresolv.so.2
librsvg-2.so.2
librtmp.so.1
libsasl2.so.2
libsecret-1.so.0
libselinux.so.1
libslang.so.2
libsmime3.so
libspiro.so.1
libsqlite3.so.0
libssh2.so.1
libssl.so.3
libstdc++.so.6
libstemmer.so.0d
libsuitesparseconfig.so.5
libsystemd.so.0
libtasn1.so.6
libtdb.so.1
libthai.so.0
libtiff.so.6
libtinfo.so.6
libtirpc.so.3
libudev.so.1
libudfread.so.0
libudisks2.so.0
libumfpack.so.5
libunistring.so.2
libunwind.so.8
libuuid.so.1
libvorbis.so.0
libvorbisfile.so.3
libwayland-client.so.0
libwayland-cursor.so.0
libwayland-egl.so.1
libwebp.so.7
libwebpdemux.so.2
libwebpmux.so.3
libwmf-0.2.so.7
libwmflite-0.2.so.7
libx265.so.199
libxapp.so.1
libxcb-render.so.0
libxcb-shm.so.0
libxcb.so.1
libxkbcommon.so.0
libxkbfile.so.1
libxklavier.so.16
libxml2.so.2
libxslt.so.1
libyaml-0.so.2
libz.so.1
libzstd.so.1

AppDir/etc have:

fonts/

[probonopd]

Where are these located on your build system? In /usr or not?

[brunvonlope]

Where are these located on your build system? In /usr or not?

As I said in #315 (comment), they come from the "system prefix" aka /usr dir

[probonopd]

Thanks. Geneally appimgetool tries to copy files into the AppDir at the same path as they are on the build system, so that the files stay at the same locations relative to each other.
Is there a symlink on your system from /lib pointing to /usr/lib or vice versa?

[brunvonlope]

Is there a symlink on your system from /lib pointing to /usr/lib or vice versa?

Yes, Debian have that exact same symlink: /lib pointing to /usr/lib