ある日こういうメッセージが出た。何をしようと下かというとrsfsというパッケージをインストールしようとしたんだ。

λ tlmgr install rsfs
tlmgr.pl: package repositories
        main = http://ftp.jaist.ac.jp/pub/CTAN/systems/texlive/tlnet (not verified: pubkey missing)
        http://ftp.yz.yamagata-u.ac.jp/pub/CTAN/systems/texlive/tlnet/ = http://ftp.yz.yamagata-u.ac.jp/pub/CTAN/systems/texlive/tlnet/ (not verified: pubkey missing)
===============================================================================
tlmgr itself needs to be updated.
Please do this via either
  tlmgr update --self
or by getting the latest updater for Unix-ish systems:
  http://mirror.ctan.org/systems/texlive/tlnet/update-tlmgr-latest.sh
and/or Windows systems:
  http://mirror.ctan.org/systems/texlive/tlnet/update-tlmgr-latest.exe
Then continue with other updates as usual.
===============================================================================
tlmgr.pl: Terminating; please see warning above!

つまり、tlmgrそのものをアップデートしろということ。コマンドも教えてくれているのでそのまま叩いた。tlmgr update --selfである。他にも方法はあるようであるが、特に他を選ぶ必要は無いな。よし。

λ tlmgr update --self
tlmgr.pl: package repositories
        main = http://ftp.jaist.ac.jp/pub/CTAN/systems/texlive/tlnet (not verified: pubkey missing)
        http://ftp.yz.yamagata-u.ac.jp/pub/CTAN/systems/texlive/tlnet/ = http://ftp.yz.yamagata-u.ac.jp/pub/CTAN/systems/texlive/tlnet/ (not verified: pubkey missing)
tlmgr.pl: saving backups to C:/texlive/2019/tlpkg/backups
tlmgr.pl: Preparing TeX Live infrastructure update...
tlmgr.pl: Backup option not implemented for infrastructure update.
DO NOT CLOSE THIS WINDOW!
TeX Live infrastructure update in progress ...
Detailed command logging to "C:\texlive\2019\temp\update-self.log"
self update: texlive.infra (51232 -> 51561) texlive.infra.win32 (50798 -> 51563)
Infrastructure update finished successfully.
You may now close this window.

これでいけたようだ。そんで、ついでに他のパッケージもアップデートしてやろう。tlmgr update --allを叩いた。その結果53個のパッケージがアップデートの対象であるようだ。perlがたくさん走ったあと、いい感じも事後処理も行ってくれているようだ。よしよし。

λ tlmgr update --all
tlmgr.pl: package repositories
        main = http://ftp.jaist.ac.jp/pub/CTAN/systems/texlive/tlnet (not verified: pubkey missing)
        http://ftp.yz.yamagata-u.ac.jp/pub/CTAN/systems/texlive/tlnet/ = http://ftp.yz.yamagata-u.ac.jp/pub/CTAN/systems/texlive/tlnet/ (not verified: pubkey missing)
tlmgr.pl: saving backups to C:/texlive/2019/tlpkg/backups
[ 1/53] auto-remove: FAQ-en ... done
[ 2/53, ??:??/??:??] update: adobemapping [2120k] (50714 -> 51787@main) ... done
[ 3/53, 00:04/03:20] update: amsmath [2362k] (49390 -> 52286@main) ... done
[ 4/53, 00:08/03:09] update: babel [1410k] (51309 -> 52241@main) ... done
[ 5/53, 00:13/03:54] update: beamer [2383k] (49306 -> 52222@main) ... done
[ 6/53, 00:21/04:29] update: bxjscls [1734k] (51463 -> 51758@main) ... done
[ 7/53, 00:24/04:15] update: cjk-gs-integrate [44k] (50214 -> 51888@main) ... done
[ 8/53, 00:25/04:24] update: etoolbox [238k] (48436 -> 52153@main) ... done
[ 9/53, 00:26/04:28] update: gentombow [548k] (48512 -> 51697@main) ... done
[10/53, 00:28/04:34] update: graphics [2017k] (47350 -> 52286@main) ... done
[11/53, 00:32/04:24] update: gsftopk.win32 [13k] (50155 -> 51902@main) ... done
[12/53, 00:32/04:24] update: hyperref [3632k] (49299 -> 52295@main) ... done
[13/53, 00:43/04:37] update: ifluatex [120k] (49285 -> 51770@main) ... done
[14/53, 00:46/04:54] update: ipaex [15501k] (45751 -> 52032@main) ... done
[15/53, 01:21/04:28] update: japanese-otf-uptex [153k] (50707 -> 52048@main) ... done
[16/53, 01:26/04:43] update: jfmutil [34k] (50002 -> 52026@main) ... done
[17/53, 01:27/04:46] update: jlreq [153k] (51036 -> 52169@main) ... done
[18/53, 01:29/04:51] update: jsclasses [979k] (50813 -> 51726@main) ... done
[19/53, 01:34/04:59] update: kpathsea [1075k] (51310 -> 52333@main) ... done
[20/53, 01:38/05:02] update: latex [16812k] (49390 -> 52286@main) ... done
[21/53, 02:21/04:52] update: latexconfig [5k] (45777 -> 52186@main) ... done
[22/53, 02:22/04:54] update: luatexja [3662k] (50978 -> 52180@main) ... done
[23/53, 02:35/04:59] update: mptopdf [52k] (50112 -> 52238@main) ... done
[24/53, 02:36/05:01] update: ms [1504k] (42428 -> 51784@main) ... done
[25/53, 02:42/05:04] update: oberdiek [14012k] (49285 -> 51770@main) ... done
[26/53, 03:20/05:01] update: pgf [10843k] (51107 -> 51817@main) ... done
[27/53, 03:44/04:52] update: platex.win32 [1k] (36810 -> 51747@main) ... done
[28/53, 03:45/04:53] update: platex [1700k] (50831 -> 52243@main) ... done
[29/53, 03:47/04:50] update: platex-tools [538k] (49250 -> 52049@main) ... done
[30/53, 03:49/04:51] update: plautopatch [141k] (51331 -> 52034@main) ... done
[31/53, 03:50/04:51] update: pxchfon [371k] (51164 -> 52325@main) ... done
[32/53, 03:52/04:53] update: tetex [584k] (51410 -> 52289@main) ... done
[33/53, 03:53/04:52] update: texlive-docindex [259k] (51466 -> 52317@main) ... done
[34/53, 03:55/04:54] update: texlive-en [1814k] (50613 -> 51878@main) ... done
[35/53, 03:59/04:52] update: texlive-msg-translations [138k] (51467 -> 52290@main) ... done
[36/53, 03:59/04:52] update: texlive-scripts.win32 [12k] (51057 -> 51991@main) ... done
[37/53, 04:00/04:53] update: texlive-scripts [134k] (51466 -> 52319@main) ... done
[38/53, 04:02/04:55] update: tlgs.win32 [6645k] (51080 -> 51941@main) ... done
[39/53, 04:11/04:44] update: tlshell.win32 [3843k] (50704 -> 52301@main) ... done
[40/53, 04:17/04:40] update: tlshell [25k] (51454 -> 52301@main) ... done
[41/53, 04:18/04:41] update: tools [5351k] (49619 -> 52286@main) ... done
[42/53, 04:32/04:41] update: unicode-data [262k] (50303 -> 51924@main) ... done
[43/53, 04:33/04:41] update: updmap-map [281k] (51410 -> 52289@main) ... done
[44/53, 04:34/04:41] update: uplatex.win32 [1k] (36810 -> 51747@main) ... done
[45/53, 04:34/04:41] update: uplatex [927k] (51191 -> 52253@main) ... done
[46/53, 04:37/04:42] update: uptex-base [166k] (51103 -> 52151@main) ... done
[47/53, 04:38/04:42] update: zxjafont [146k] (47613 -> 51531@main) ... done
[48/53, 04:39/04:43] auto-install: bxghost (52150@main) [4k] ... done
[49/53, 04:40/04:44] auto-install: ifplatform (45533@main) [156k] ... done
[50/53, 04:41/04:44] auto-install: texlive-ja (51990@main) [1468k] ... done
[51/53, 04:44/04:44] update: collection-basic [1k] (51464 -> 51558@main) ... done
[52/53, 04:44/04:44] update: collection-langenglish [1k] (50985 -> 52239@main) ... done
[53/53, 04:45/04:45] update: collection-langjapanese [1k] (49995 -> 52150@main) ... done
running mktexlsr ...
done running mktexlsr.
running updmap-sys ...
done running updmap-sys.
regenerating fmtutil.cnf in C:/texlive/2019/texmf-dist
running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --no-error-if-no-format --byengine luatex ...
done running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --no-error-if-no-format --byengine luatex.
running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --no-error-if-no-format --byengine uptex ...
done running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --no-error-if-no-format --byengine uptex.
running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --no-error-if-no-format --byengine luajittex ...
done running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --no-error-if-no-format --byengine luajittex.
running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --no-error-if-no-format --byengine euptex ...
done running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --no-error-if-no-format --byengine euptex.
running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --byfmt mptopdf ...
done running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --byfmt mptopdf.
running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --byfmt platex-dev ...
done running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --byfmt platex-dev.
running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --byfmt pdflatex ...
done running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --byfmt pdflatex.
running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --byfmt platex ...
done running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --byfmt platex.
running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --byfmt latex ...
done running fmtutil-sys --no-error-if-no-engine=luajittex,mfluajit --byfmt latex.
tlmgr.pl: package log updated: C:/texlive/2019/texmf-var/web2c/tlmgr.log

結論

tlmgrは神。