While output of fc-list as below is not inteligible for charset, I can see
charset shown properly under 'FC_DEBUG=8 fc-list ...' (too long to report here)
or 'FC_DEBUG=1 fc-match serif' as below.
== OUTPUT EXAMPLES ==
osamu@snoopy:~$ fc-list "Bitstream Vera Serif" charset
:charset= |>^1!|>^1!P0oWQ |>^1!|>^1!|>^1!!!!%#gfN8.!!B7%ggR6OF3y?4!!K?& !!!)$ 9;*f! !!!.% !!!)$!!!!# !!#0GM>RAd#y#fx!!!!5 !!!W5 !!#3H !!!!& !!#6I<UKaX!!!?+!!!%#!!!!X !!#AL !!!1& !!+u{!!!!)
osamu@snoopy:~$ FC_DEBUG=1 fc-match serif
FC_DEBUG=1
FC_DEBUG=1
Match Pattern has 17 elts (size 32)
family: "Bitstream Vera Serif"(w) "DejaVu Serif"(w) "Times New Roman"(w) "Thorndale AMT"(w) "Luxi Serif"(w) "Nimbus Roman No9 L"(w) "Times"(w) "Artsounk"(w) "BPG UTF8 M"(w) "Phaisarn"(w) "Phaisarn98"(w) "Norasi"(w) "Frank Ruehl"(w) "Dror"(w) "JG LaoTimes"(w) "Saysettha Unicode"(w) "Pigiarniq"(w) "B Davat"(w) "B Compset"(w) "Kacst-Qr"(w) "Urdu Nastaliq Unicode"(w) "Raghindi"(w) "Mukti Narrow"(w) "malayalam"(w) "Sampige"(w) "padmaa"(w) "Hapax Berbère"(w) "MS Gothic"(w) "UmePlus P Gothic"(w) "SimSun"(w) "PMingLiu"(w) "AR PL ShanHeiSun Uni"(w) "AR PL New Sung"(w) "ZYSong18030"(w) "HanyiSong"(w) "MgOpen Canonica"(w) "Sazanami Mincho"(w) "IPAMonaMincho"(w) "IPAMincho"(w) "Kochi Mincho"(w) "AR PL SungtiL GB"(w) "AR PL Mingti2L Big5"(w) "AR PL Zenkai Uni"(w) "ＭＳ 明朝"(w) "ZYSong18030"(w) "UnBatang"(w) "Baekmuk Batang"(w) "KacstQura"(w) "Frank Ruehl CLM"(w) "Lohit Bengali"(w) "Lohit Gujarati"(w) "Lohit Hindi"(w) "Lohit Punjabi"(w) "Lohit Tamil"(w) "Lohit Malayalam"(w) "Lohit Kannada"(w) "Lohit Telugu"(w) "Lohit Oriya"(w) "LKLUG"(w) "FreeSerif"(w) "Code2000"(w) "Code2001"(w) "serif"(s) "Nazli"(w) "Lotoos"(w) "Mitra"(w) "Ferdosi"(w) "Badr"(w) "Zar"(w) "LMRoman10-Regular"(w)
slant: 0(i)(s)
weight: 100(i)(s)
width: 100(i)(s)
size: 12(f)(s)
pixelsize: 12.5(f)(s)
hintstyle: 3(i)(s)
hinting: FcTrue(s)
verticallayout: FcFalse(s)
autohint: FcFalse(s)
globaladvance: FcTrue(s)
dpi: 75(f)(s)
scale: 1(f)(s)
lang: "en-US"(s)
fontversion: 2147483647(i)(s)
embeddedbitmap: FcTrue(s)
decorative: FcFalse(s)
Best score 0 0 162 100 0 0 0 0 0 2000 0 0 0 0 0 2.14735e+11Pattern has 19 elts (size 19)
family: "Bitstream Vera Serif"(w)
familylang: "en"(w)
style: "Roman"(w)
stylelang: "en"(w)
fullname: "Bitstream Vera Serif"(w)
fullnamelang: "en"(w)
slant: 0(i)(w)
weight: 80(i)(w)
width: 100(i)(w)
foundry: "bitstream"(w)
file: "/usr/share/fonts/truetype/ttf-bitstream-vera/VeraSe.ttf"(w)
index: 0(i)(w)
outline: FcTrue(w)
scalable: FcTrue(w)
charset: 0000: 00000000 ffffffff ffffffff 7fffffff 00000000 ffffffff ffffffff ffffffff
0001: c00230c0 00030000 c00c0006 61000003 00040000 00000000 00000000 00000000
0002: 00000000 00000000 00000000 00000000 00000000 00000000 3f0000c0 00000000
0003: 00000000 00000000 00000000 00000000 00000000 00000200 00000001 00000000
0020: 77180000 06010047 00000010 00000000 00000000 00001000 00000000 00000000
0021: 00000000 00000004 00000000 00000000 00000000 00000000 00000000 00000000
0022: 46268044 00000800 00000100 00000031 00000000 00000000 00000000 00000000
0025: 00000000 00000000 00000000 00000000 00000000 00000000 00000400 00000000
00fb: 00000006 00000000 00000000 00000000 00000000 00000000 00000000 00000000
(w)
lang: aa|ast|ay|bi|br|ch|co|da|de|en|es|et|eu|fi|fj|fo|fr|fur|fy|gd|gl|gv|ho|ia|id|ie|io|is|it|lb|mg|nb|nds|nl|nn|no|nr|nso|oc|om|pt|rm|sma|smj|so|sq|ss|st|sv|sw|tn|tr|ts|vo|vot|wa|xh|yap|zu(w)
fontversion: 131072(i)(w)
fontformat: "TrueType"(w)
decorative: FcFalse(w)
VeraSe.ttf: "Bitstream Vera Serif" "Roman"