SyntaxError: unknown encoding: big5 - Buildroot Error

Question

I'm trying to add joblib in my Linux embedded environment through Buildroot. As it is not part of the default Buildroot menu for Python3 packages, I added it with the scanpypi script from Buildroot and followed the user manual instructions to add it in the menu and select it. I then ran make but it seems there is a problem with the joblib library : Here is what I get.

>>> python-joblib 1.1.0 Installing to target

<a ton of logs about the installation>

>>>   Finalizing host directory
>>>   Finalizing target directory
mkdir -p /home/mso-aerosat/Desktop/cecilia_workspace/Buildroot/buildroot-2021.02.7/output
/host/etc/meson
sed -e 's%@TARGET_CROSS@%/home/mso-aerosat/Desktop/cecilia_workspace/Buildroot/buildroot-
2021.02.7/output/host/bin/arm-buildroot-linux-gnueabihf-%g' -e 's%@TARGET_ARCH@%arm%g' -e 
's%@TARGET_CPU@%cortex-a9%g' -e 's%@TARGET_ENDIAN@%little%g' -e "s%@TARGET_CFLAGS@%'-
D_LARGEFILE_SOURCE', '-D_LARGEFILE64_SOURCE', '-D_FILE_OFFSET_BITS=64', 
'-Os'@PKG_TARGET_CFLAGS@%g" -e "s%@TARGET_LDFLAGS@%@PKG_TARGET_CFLAGS@%g" -e 
"s%@TARGET_CXXFLAGS@%'-D_LARGEFILE_SOURCE', '-D_LARGEFILE64_SOURCE', 
'-D_FILE_OFFSET_BITS=64', '-Os'@PKG_TARGET_CFLAGS@%g" -e 's%@HOST_DIR@%/home/mso-aerosat
/Desktop/cecilia_workspace/Buildroot/buildroot-2021.02.7/output/host%g' -e 
's%@STAGING_DIR@%/home/mso-aerosat/Desktop/cecilia_workspace/Buildroot/buildroot-
2021.02.7/output/host/arm-buildroot-linux-gnueabihf/sysroot%g' -e 's%@STATIC@%false%g' 
package/meson//cross-compilation.conf.in > /home/mso-aerosat/Desktop/cecilia_workspace
/Buildroot/buildroot-2021.02.7/output/host/etc/meson/cross-compilation.conf.in
sed -e 's%@PKG_TARGET_CFLAGS@%%g' -e 's%@PKG_TARGET_LDFLAGS@%%g' -e 
's%@PKG_TARGET_CXXFLAGS@%%g' /home/mso-aerosat/Desktop/cecilia_workspace/Buildroot
/buildroot-2021.02.7/output/host/etc/meson/cross-compilation.conf.in > /home/mso-aerosat
/Desktop/cecilia_workspace/Buildroot/buildroot-2021.02.7/output/host/etc/meson/cross-
compilation.conf
/usr/bin/sed -i -e '/# GENERIC_SERIAL$/s~^.*#~ttyPS0::respawn:/sbin/getty -L  ttyPS0 0 
vt100 #~' /home/mso-aerosat/Desktop/cecilia_workspace/Buildroot/buildroot-2021.02.7
/output/target/etc/inittab
/usr/bin/sed -i -e '/^#.*-o remount,rw \/$/s~^#\+~~' /home/mso-aerosat/Desktop
/cecilia_workspace/Buildroot/buildroot-2021.02.7/output/target/etc/inittab
if grep -q CONFIG_ASH=y /home/mso-aerosat/Desktop/cecilia_workspace/Buildroot/buildroot-
2021.02.7/output/build/busybox-1.33.1/.config; then grep -qsE '^/bin/ash$' /home/mso-
aerosat/Desktop/cecilia_workspace/Buildroot/buildroot-2021.02.7/output/target/etc/shells 
|| echo "/bin/ash" >> /home/mso-aerosat/Desktop/cecilia_workspace/Buildroot/buildroot-
2021.02.7/output/target/etc/shells; fi
if grep -q CONFIG_HUSH=y /home/mso-aerosat/Desktop/cecilia_workspace/Buildroot/buildroot-
2021.02.7/output/build/busybox-1.33.1/.config; then grep -qsE '^/bin/hush$' /home/mso-
aerosat/Desktop/cecilia_workspace/Buildroot/buildroot-2021.02.7/output/target/etc/shells 
|| echo "/bin/hush" >> /home/mso-aerosat/Desktop/cecilia_workspace/Buildroot/buildroot-
2021.02.7/output/target/etc/shells; fi
PYTHONPATH="/home/mso-aerosat/Desktop/cecilia_workspace/Buildroot/buildroot-2021.02.7
/output/host/arm-buildroot-linux-gnueabihf/sysroot/usr/lib/python3.9/" /home/mso-aerosat
/Desktop/cecilia_workspace/Buildroot/buildroot-2021.02.7/output/host/bin/python3.9 
/home/mso-aerosat/Desktop/cecilia_workspace/Buildroot/buildroot-2021.02.7/support/scripts
/pycompile.py  --strip-root /home/mso-aerosat/Desktop/cecilia_workspace/Buildroot
/buildroot-2021.02.7/output/target /home/mso-aerosat/Desktop/cecilia_workspace/Buildroot
/buildroot-2021.02.7/output/target/usr/lib/python3.9
error:   File "/usr/lib/python3.9/site-packages/joblib/test/test_func_inspect_special_encoding.py", line 0
SyntaxError: unknown encoding: big5

make[1]: *** [Makefile:753: target-finalize] Error 1
make: *** [Makefile:84: _all] Error 2

As you can see it's complaining about the encoding of a file. But I have no idea what I can do about it... Has anyone any idea ?