OCRmyPDF错误：无法获取http://security.ubuntu.com/

Question

我正在使用GoogleColab运行我的Python代码。今天，当我运行!apt-get install ocrmypdf -q时，我得到以下“无法获取”错误。知道它为什么会出现以及如何修复吗？谢谢

顺便说一句，昨天代码运行得很好

Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  fonts-droid-fallback fonts-noto-mono ghostscript gsfonts icc-profiles-free
  libart-2.0-2 libcupsfilters1 libcupsimage2 libgs9 libgs9-common libijs-0.35
  libjbig2dec0 libqpdf21 poppler-data python3-cffi-backend python3-defusedxml
  python3-img2pdf python3-olefile python3-pil python3-pkg-resources
  python3-pypdf2 python3-renderpm python3-reportlab python3-reportlab-accel
  python3-ruffus qpdf tesseract-ocr tesseract-ocr-eng tesseract-ocr-osd
  unpaper
Suggested packages:
  fonts-noto ghostscript-x ocrmypdf-doc python-watchdog img2pdf poppler-utils
  fonts-japanese-mincho | fonts-ipafont-mincho fonts-japanese-gothic
  | fonts-ipafont-gothic fonts-arphic-ukai fonts-arphic-uming fonts-nanum
  python3-pdfrw python-pil-doc python3-pil-dbg python3-setuptools
  python3-renderpm-dbg pdf-viewer python3-egenix-mxtexttools
  python-reportlab-doc
The following NEW packages will be installed:
  fonts-droid-fallback fonts-noto-mono ghostscript gsfonts icc-profiles-free
  libart-2.0-2 libcupsfilters1 libcupsimage2 libgs9 libgs9-common libijs-0.35
  libjbig2dec0 libqpdf21 ocrmypdf poppler-data python3-cffi-backend
  python3-defusedxml python3-img2pdf python3-olefile python3-pil
  python3-pkg-resources python3-pypdf2 python3-renderpm python3-reportlab
  python3-reportlab-accel python3-ruffus qpdf tesseract-ocr tesseract-ocr-eng
  tesseract-ocr-osd unpaper
0 upgraded, 31 newly installed, 0 to remove and 16 not upgraded.
Need to get 7,407 kB/21.6 MB of archives.
After this operation, 75.8 MB of additional disk space will be used.
Ign:1 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 libgs9-common all 9.26~dfsg+0-0ubuntu0.18.04.13
Ign:2 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 libgs9 amd64 9.26~dfsg+0-0ubuntu0.18.04.13
Ign:3 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 ghostscript amd64 9.26~dfsg+0-0ubuntu0.18.04.13
Err:1 http://security.ubuntu.com/ubuntu bionic-updates/main amd64 libgs9-common all 9.26~dfsg+0-0ubuntu0.18.04.13
  404  Not Found [IP: 91.189.88.142 80]
Err:2 http://security.ubuntu.com/ubuntu bionic-updates/main amd64 libgs9 amd64 9.26~dfsg+0-0ubuntu0.18.04.13
  404  Not Found [IP: 91.189.88.142 80]
Err:3 http://security.ubuntu.com/ubuntu bionic-updates/main amd64 ghostscript amd64 9.26~dfsg+0-0ubuntu0.18.04.13
  404  Not Found [IP: 91.189.88.142 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/main/g/ghostscript/libgs9-common_9.26~dfsg+0-0ubuntu0.18.04.13_all.deb  404  Not Found [IP: 91.189.88.142 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/main/g/ghostscript/libgs9_9.26~dfsg+0-0ubuntu0.18.04.13_amd64.deb  404  Not Found [IP: 91.189.88.142 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/main/g/ghostscript/ghostscript_9.26~dfsg+0-0ubuntu0.18.04.13_amd64.deb  404  Not Found [IP: 91.189.88.142 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?