Problem with updmap directories in TexLive

README.md

https://www.overleaf.com/learn/latex/Articles/An_introduction_to_Kpathsea_and_how_TeX_engines_search_for_files#Brief_notes_on_.24TEXMF

mkdir -p bug
cd bug

wget https://gist.github.com/vadimkantorov/cb638c61afc2fb4526d05e6c4c3b48b6/raw/db85459a69ab82686a8d42ffb9a2f8895a977e41/texlive.sh
wget https://gist.github.com/vadimkantorov/cb638c61afc2fb4526d05e6c4c3b48b6/raw/db85459a69ab82686a8d42ffb9a2f8895a977e41/latex.sh
wget https://gist.github.com/vadimkantorov/cb638c61afc2fb4526d05e6c4c3b48b6/raw/2b1953f48a329cc30a5d25fd6e34dddb6db90849/bug.sh

MAKEFLAGS=-j4 bash texlive.sh
bash latex.sh

bash bug.sh

xdvipdfmx -o example.pdf example.xdv prints:

...
xdvipdfmx:warning: Couldn't open font map file "pdftex.map".
xdvipdfmx:warning: Couldn't open font map file "kanjix.map".

kpsewhich -debug 32 pdftex.map prints:

kdebug:start search(xname=texmf.cnf, must_exist=1, find_all=1, path=/mnt/c/Users/user/busytex/bug2/texlive/texmf-dist/web2c).
kdebug: path_search(file=texmf.cnf, must_exist=1, find_all=1, path=/mnt/c/Users/user/busytex/bug2/texlive/texmf-dist/web2c)
kdebug:  dir_list_search(file=texmf.cnf, find_all=1, casefold=no)
kdebug:start generic search(files=[ls-r ls-R], must_exist=1, find_all=1, path=/mnt/c/Users/user/busytex/bug2/texmf-local:/mnt/c/Users/user/busytex/bug2/build/texmf-config:/mnt/c/Users/user/busytex/bug2/build/texmf-var:/mnt/c/Users/user/busytex/bug2/texlive/texmf-dist)
kdebug:  dir_list_search_list(files=[ls-r ls-R], find_all=1, casefold=no)
kdebug:returning from generic search([ls-r ls-R]) => /mnt/c/Users/user/busytex/bug2/texlive/texmf-dist/ls-r /mnt/c/Users/user/busytex/bug2/texlive/texmf-dist/ls-R
kdebug:start search(xname=aliases, must_exist=1, find_all=1, path=/mnt/c/Users/user/busytex/bug2/texmf-local:/mnt/c/Users/user/busytex/bug2/build/texmf-config:/mnt/c/Users/user/busytex/bug2/build/texmf-var:/mnt/c/Users/user/busytex/bug2/texlive/texmf-dist).
kdebug: path_search(file=aliases, must_exist=1, find_all=1, path=/mnt/c/Users/user/busytex/bug2/texmf-local:/mnt/c/Users/user/busytex/bug2/build/texmf-config:/mnt/c/Users/user/busytex/bug2/build/texmf-var:/mnt/c/Users/user/busytex/bug2/texlive/texmf-dist)
kdebug:  dir_list_search(file=aliases, find_all=1, casefold=no)
kdebug:  dir_list_search(file=aliases, find_all=1, casefold=yes)
kdebug:   casefold_readable_file(aliases) in /mnt/c/Users/user/busytex/bug2/texlive/texmf-dist => (nil)
kdebug:returning from search(aliases) =>
kdebug:kpse_find_file: searching for pdftex.map of type map (from texmf.cnf)
kdebug:start generic search(files=[pdftex.map], must_exist=0, find_all=0, path=.:/home/vadimkantorov/.texlive2020/texmf-config/fonts/map/kpsewhich//:/home/vadimkantorov/.texlive2020/texmf-var/fonts/map/kpsewhich//:/home/vadimkantorov/texmf/fonts/map/kpsewhich//:!!/mnt/c/Users/user/busytex/bug2/texmf-local/fonts/map/kpsewhich//:!!/mnt/c/Users/user/busytex/bug2/build/texmf-config/fonts/map/kpsewhich//:!!/mnt/c/Users/user/busytex/bug2/build/texmf-var/fonts/map/kpsewhich//:!!/mnt/c/Users/user/busytex/bug2/texlive/texmf-dist/fonts/map/kpsewhich//:/home/vadimkantorov/.texlive2020/texmf-config/fonts/map/pdftex//:/home/vadimkantorov/.texlive2020/texmf-var/fonts/map/pdftex//:/home/vadimkantorov/texmf/fonts/map/pdftex//:!!/mnt/c/Users/user/busytex/bug2/texmf-local/fonts/map/pdftex//:!!/mnt/c/Users/user/busytex/bug2/build/texmf-config/fonts/map/pdftex//:!!/mnt/c/Users/user/busytex/bug2/build/texmf-var/fonts/map/pdftex//:!!/mnt/c/Users/user/busytex/bug2/texlive/texmf-dist/fonts/map/pdftex//:/home/vadimkantorov/.texlive2020/texmf-config/fonts/map/dvips//:/home/vadimkantorov/.texlive2020/texmf-var/fonts/map/dvips//:/home/vadimkantorov/texmf/fonts/map/dvips//:!!/mnt/c/Users/user/busytex/bug2/texmf-local/fonts/map/dvips//:!!/mnt/c/Users/user/busytex/bug2/build/texmf-config/fonts/map/dvips//:!!/mnt/c/Users/user/busytex/bug2/build/texmf-var/fonts/map/dvips//:!!/mnt/c/Users/user/busytex/bug2/texlive/texmf-dist/fonts/map/dvips//:/home/vadimkantorov/.texlive2020/texmf-config/fonts/map///:/home/vadimkantorov/.texlive2020/texmf-var/fonts/map///:/home/vadimkantorov/texmf/fonts/map///:!!/mnt/c/Users/user/busytex/bug2/texmf-local/fonts/map///:!!/mnt/c/Users/user/busytex/bug2/build/texmf-config/fonts/map///:!!/mnt/c/Users/user/busytex/bug2/build/texmf-var/fonts/map///:!!/mnt/c/Users/user/busytex/bug2/texlive/texmf-dist/fonts/map///)
kdebug:  dir_list_search_list(files=[pdftex.map], find_all=0, casefold=no)
kdebug:  dir_list_search_list(files=[pdftex.map], find_all=0, casefold=yes)
kdebug:   casefold_readable_file(pdftex.map) in . => (nil)
kdebug:returning from generic search([pdftex.map]) =>

The {pdfmap,kanjix}.map files exist, but they are under updmap directory which is not present in default texmf.cnf:

find texlive -name pdftex.map
# texlive/texmf-var/fonts/map/pdftex/updmap/pdftex.map

find texlive -name kanjix.map
# texlive/texmf-var/fonts/map/dvipdfmx/updmap/kanjix.map

find texlive -name texmf.cnf
# texlive/texmf-dist/web2c/texmf.cnf
# texlive/texmf.cnf

grep 'fonts/map' texlive/texmf-dist/web2c/texmf.cnf
# TEXFONTMAPS = $TEXMFDOTDIR;$TEXMF/fonts/map/{$progname,pdftex,dvips,}//

Working directory is /mnt/c/Users/user/busytex/bug2/, the system is Ubuntu 18.04 on WSLv1, case-insensitive mount point.

bug.sh

LATEXFMT=$PWD/latex-format/latex.fmt

kpsewhich=$PWD/build/texk/kpathsea/kpsewhich
xetex=$PWD/build/texk/web2c/xetex
xdvipdfmx=$PWD/build/texk/dvipdfm-x/xdvipdfmx

export TEXMFCNF=$PWD/texlive/texmf-dist/web2c
export TEXMFDIST=$PWD/texlive/texmf-dist
export TEXMFVAR=$PWD/texlive/texmf-var
echo '\documentclass[11pt]{article}\begin{document}Hello world\end{document}' > example.tex

$xetex --interaction=nonstopmode --halt-on-error --no-pdf --fmt $LATEXFMT example.tex
$xdvipdfmx -o example.pdf example.xdv

$kpsewhich -debug 32 pdftex.map

latex.sh

xetex=$PWD/build/texk/web2c/xetex

URL_TEXLIVE_INSTALLER=http://mirror.ctan.org/systems/texlive/tlnet/install-tl-unx.tar.gz

wget -nc $URL_TEXLIVE_INSTALLER

mkdir -p install-tl latex-format
tar -xf install-tl-unx.tar.gz --strip-components=1 --directory=install-tl

echo selected_scheme scheme-basic > install-tl.profile
echo TEXDIR $PWD/texlive >> install-tl.profile
echo TEXMFVAR $PWD/texlive/texmf-var >> install-tl.profile
echo TEXMFLOCAL $PWD/texlive/texmf-local >> install-tl.profile
echo TEXMFSYSCONFIG $PWD/texlive/texmf-config >> install-tl.profile
echo TEXMFSYSVAR $PWD/texlive/texmf-var >> install-tl.profile
TEXLIVE_INSTALL_NO_RESUME=1 $PWD/install-tl/install-tl -profile install-tl.profile

TEXINPUTS=texlive/texmf-dist/source/latex/base TEXMFCNF=texlive/texmf-dist/web2c TEXMFDIST=texlive/texmf-dist $xetex --interaction=nonstopmode --halt-on-error --output-directory=./latex-format -ini -etex unpack.ins
TEXINPUTS=texlive/texmf-dist/source/latex/base:texlive/texmf-dist/tex/generic/unicode-data:texlive/texmf-dist/tex/latex/base:texlive/texmf-dist/tex/generic/hyphen:texlive/texmf-dist/tex/latex/l3kernel:texlive/texmf-dist/tex/latex/l3packages/xparse TEXMFCNF=texlive/texmf-dist/web2c TEXMFDIST=texlive/texmf-dist $xetex --interaction=nonstopmode --halt-on-error --output-directory=./latex-format -ini -etex latex.ltx
~                                                                                                                               

texlive.sh

URL_texlive=https://github.com/TeX-Live/texlive-source/archive/9ed922e7d25e41b066f9e6c973581a4e61ac0328.tar.gz
PREFIX=$PWD/prefix
CACHE=$PWD/config.cache
TEXLIVESRC=$PWD/texlive-source
TEXLIVEBLD=$PWD/build

mkdir -p $PREFIX $TEXLIVESRC $TEXLIVEBLD

wget -nc $URL_texlive
tar -xf $(basename $URL_texlive) --strip-components=1 --directory=$TEXLIVESRC
pushd $TEXLIVESRC/texk
rm -rf upmendex dviout-util dvipsk gxdvik dviljk dvipos dvidvi dvipng dvi2tty dvisvgm dtl gregorio cjkutils musixtnt tests ttf2pk2 ttfdump makejvf lcdf-typetools
popd

pushd $TEXLIVEBLD

bash $TEXLIVESRC/configure                        \
  --cache-file=$CACHE                             \
  --prefix=$PREFIX                                \
  --disable-all-pkgs                              \
  --disable-multiplatform                         \
  --enable-static                                 \
  --disable-shared                                \
  --enable-web2c                                  \
  --enable-xetex                                  \
  --enable-dvipdfm-x                              \
  --without-x                                     \
  --without-system-kpathsea                       \
  --without-system-ptexenc                        \
  --without-system-cairo                          \
  --without-system-gmp                            \
  --without-system-graphite2                      \
  --without-system-harfbuzz                       \
  --without-system-libgs                          \
  --without-system-libpaper                       \
  --without-system-mpfr                           \
  --without-system-pixman                         \
  --without-system-poppler                        \
  --without-system-xpdf                           \
  --without-system-icu                            \
  --without-system-fontconfig                     \
  --without-system-freetype2                      \
  --without-system-libpng                         \
  --without-system-zlib

make $MAKEFLAGS