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Fix MATLAB R2020a Installer on Modern Ubuntu: GLib, Pango, and FreeType

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MATLAB R2020a is old enough that its Linux installer can fail on a current Ubuntu release before the installer window appears:

terminate called after throwing an instance of 'std::runtime_error'
what(): Unable to launch the MATLABWindow application

The useful error is visible by running the window program directly:

./bin/glnxa64/MATLABWindow -help

On this system it reported:

symbol lookup error: /lib/x86_64-linux-gnu/libpango-1.0.so.0: \
undefined symbol: g_once_init_leave_pointer

Tested Environment

This workaround was tested on:

Ubuntu 24.04.1 LTS (Noble Numbat), x86_64
MATLAB R2020a (9.8.0)

Cause

R2020a bundles an old GLib 2.56-era runtime under:

cefclient/sys/os/glnxa64/

but does not bundle Pango or Cairo. Therefore it loads Ubuntu’s current Pango/Cairo libraries while its RPATH still selects the bundled libglib-2.0.so.0 and libgobject-2.0.so.0.

Modern Pango requires g_once_init_leave_pointer, which the bundled GLib does not export. The system GLib does:

nm -D ./cefclient/sys/os/glnxa64/libglib-2.0.so.0.5600.1 \
  | grep g_once_init_leave_pointer

nm -D /lib/x86_64-linux-gnu/libglib-2.0.so.0 \
  | grep g_once_init_leave_pointer

The first command has no output; the second prints the exported symbol.

Use a Writable Copy of the Installation Media

Do not change the mounted ISO. First copy its contents to a writable directory:

cp -a /path/to/mounted/MATHWORKS_R2020A /work/tools/matlab2020a/MATHWORKS_R2020A
cd /work/tools/matlab2020a/MATHWORKS_R2020A

If the copied directory still has read-only directory permissions, make only the runtime-library directory writable:

chmod u+w cefclient/sys/os/glnxa64

Reusable Repair Script

The following script accepts an explicit MATLAB root, so it works for either the writable installation-media copy or the installed MATLAB tree. It replaces SONAME entry points rather than versioned files, and retains every original beside it with a .matlab-r2020a-bundled suffix.

#!/usr/bin/env bash
# Repair MATLAB R2020a's bundled GLib/FreeType runtime on current Ubuntu.
# Usage: fix-matlab-r2020a-runtime.sh /path/to/MATLAB_R2020A

set -euo pipefail

backup_suffix='.matlab-r2020a-bundled'
system_lib_dir='/lib/x86_64-linux-gnu'

usage() {
    cat <<'EOF'
Usage: fix-matlab-r2020a-runtime.sh MATLAB_ROOT

Replace MATLAB R2020a's old bundled runtime entry points with compatible
system libraries. The original entry point for each changed library is kept
beside it with the suffix .matlab-r2020a-bundled.

Examples:
  fix-matlab-r2020a-runtime.sh /work/tools/matlab2020a/MATHWORKS_R2020A
  fix-matlab-r2020a-runtime.sh /work/app/matlab/2020a
EOF
}

fail() {
    printf 'error: %s\n' "$*" >&2
    exit 1
}

if [[ $# -ne 1 || $1 == '-h' || $1 == '--help' ]]; then
    usage
    [[ $# -eq 1 ]] && exit 0
    exit 2
fi

matlab_root=$(cd "$1" 2>/dev/null && pwd -P) \
    || fail "MATLAB root does not exist: $1"
bin_dir="$matlab_root/bin/glnxa64"
cef_dir="$matlab_root/cefclient/sys/os/glnxa64"

[[ -d $bin_dir ]] || fail "not an R2020a Linux runtime (missing $bin_dir)"
[[ -d $cef_dir ]] || fail "not an R2020a Linux runtime (missing $cef_dir)"
[[ -w $bin_dir ]] || fail "$bin_dir is not writable; copy the installation media first or run: chmod u+w '$bin_dir'"
[[ -w $cef_dir ]] || fail "$cef_dir is not writable; copy the installation media first or run: chmod u+w '$cef_dir'"

for lib in libfreetype.so.6 libglib-2.0.so.0 libgobject-2.0.so.0 libgio-2.0.so.0 libgmodule-2.0.so.0; do
    [[ -e "$system_lib_dir/$lib" ]] || fail "required system library is missing: $system_lib_dir/$lib"
done

nm -D "$system_lib_dir/libfreetype.so.6" 2>/dev/null \
    | awk '$NF == "FT_Get_Color_Glyph_Layer" { found = 1 } END { exit !found }' \
    || fail "system FreeType does not export FT_Get_Color_Glyph_Layer"

ensure_override() {
    local path=$1
    local system_lib=$2
    local backup="${path}${backup_suffix}"
    local resolved_path resolved_system

    [[ -e $path || -L $path ]] || fail "MATLAB library is missing: $path"
    resolved_path=$(readlink -f "$path")
    resolved_system=$(readlink -f "$system_lib")

    if [[ $resolved_path == "$resolved_system" ]]; then
        printf 'unchanged: %s already resolves to %s\n' "$path" "$resolved_system"
        return
    fi

    [[ ! -e $backup && ! -L $backup ]] \
        || fail "backup already exists; refusing to overwrite: $backup"

    mv "$path" "$backup"
    ln -s "$system_lib" "$path"
    printf 'updated: %s -> %s\n' "$path" "$system_lib"
    printf 'backup:  %s\n' "$backup"
}

ensure_override "$bin_dir/libfreetype.so.6" "$system_lib_dir/libfreetype.so.6"
ensure_override "$cef_dir/libglib-2.0.so.0" "$system_lib_dir/libglib-2.0.so.0"
ensure_override "$cef_dir/libgobject-2.0.so.0" "$system_lib_dir/libgobject-2.0.so.0"
ensure_override "$cef_dir/libgio-2.0.so.0" "$system_lib_dir/libgio-2.0.so.0"
ensure_override "$cef_dir/libgmodule-2.0.so.0" "$system_lib_dir/libgmodule-2.0.so.0"

cat <<EOF

Done. Verify the resolved libraries with:
  LD_TRACE_LOADED_OBJECTS=1 "$bin_dir/MATLABWindow" 2>&1 | grep -E 'lib(freetype|glib|gobject|gio|gmodule)-[^ ]*'

To restore an overridden library, remove its symlink and rename its backup:
  rm PATH_TO_LIBRARY
  mv PATH_TO_LIBRARY${backup_suffix} PATH_TO_LIBRARY
EOF

Save it as fix-matlab-r2020a-runtime.sh and make it executable:

chmod 755 fix-matlab-r2020a-runtime.sh

Run it against the writable installation-media copy before launching the installer:

./fix-matlab-r2020a-runtime.sh /work/tools/matlab2020a/MATHWORKS_R2020A

After installation, run the same script against the installed MATLAB root. This is necessary because the installer-media changes do not carry into the installed application:

./fix-matlab-r2020a-runtime.sh /work/app/matlab/2020a

libglib and libgobject fix the original Pango error. On this Ubuntu version, loading the modern system libgio was also necessary, followed by its matching libgmodule:

libgdk_pixbuf-2.0.so.0: undefined symbol: g_task_set_static_name
libgio-2.0.so.0: undefined symbol: g_module_open_full

libgthread-2.0.so.0 did not need replacement.

The script also uses system FreeType. This is needed for modern system HarfBuzz, which requires FT_Get_Color_Glyph_Layer; MATLAB’s bundled FreeType does not export that symbol. It is the failure that appears when creating a new Simulink model:

Bundle#59 start failed: /lib/x86_64-linux-gnu/libharfbuzz.so.0: \
undefined symbol: FT_Get_Color_Glyph_Layer

Verify and Run

The dynamic loader should now resolve FreeType and the four GLib-family libraries through local symlinks, which point to Ubuntu’s versions:

LD_TRACE_LOADED_OBJECTS=1 ./bin/glnxa64/MATLABWindow 2>&1 \
  | grep -E 'lib(freetype|glib|gobject|gio|gmodule)-[^ ]*'

Then launch the installer normally:

./install

Missing optional GTK modules such as gail, atk-bridge, or canberra-gtk-module may be printed as warnings. They are unrelated to the GLib symbol failure. No system packages or system library files need to be changed for this workaround.

Restore the Bundled Libraries

To undo the workaround, remove each symlink and move its backup back. For example, for the GLib-family libraries:

cd /work/tools/matlab2020a/MATHWORKS_R2020A

for lib in \
  libglib-2.0.so.0 \
  libgobject-2.0.so.0 \
  libgio-2.0.so.0 \
  libgmodule-2.0.so.0
do
  rm "cefclient/sys/os/glnxa64/$lib"
  mv "cefclient/sys/os/glnxa64/$lib.matlab-r2020a-bundled" \
     "cefclient/sys/os/glnxa64/$lib"
done

Restore the FreeType file from its own backup in the same way if needed.

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