我在使用 qt 时遇到了类似的问题，所以我这样做了，并且成功了： https://askubuntu.com/a/1274166/806813
但对于这个，我只能找到： http://neuro.debian.net/install_pkg.html?p=libvtk5-qt4-dev
更新时出现错误：
sudo apt-get update
Get:1 http://neuro.debian.net/debian data InRelease [30.2 kB]
Hit:2 http://ppa.launchpad.net/rock-core/qt4/ubuntu focal InRelease
Err:1 http://neuro.debian.net/debian data InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A5D32F012649A5A9
Get:3 http://neuro.debian.net/debian focal InRelease [18.2 kB]
Err:3 http://neuro.debian.net/debian focal InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A5D32F012649A5A9
Hit:4 http://security.ubuntu.com/ubuntu focal-security InRelease
Hit:5 http://archive.ubuntu.com/ubuntu focal InRelease
Hit:6 http://security.ubuntu.com/ubuntu bionic-security InRelease
Hit:7 http://archive.ubuntu.com/ubuntu focal-updates InRelease
Hit:8 http://archive.ubuntu.com/ubuntu focal-backports InRelease
Reading package lists... Done
W: GPG error: http://neuro.debian.net/debian data InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A5D32F012649A5A9
E: The repository 'http://neuro.debian.net/debian data InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://neuro.debian.net/debian focal InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A5D32F012649A5A9
E: repository 'http://neuro.debian.net/debian focal InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details
我想要的包裹的完整清单是：
sudo apt-get -y install autoconf build-essential checkinstall git subversion libfaac-dev libgpac-dev libjack-jackd2-dev libmp3lame-dev libopencore-amrnb-dev libopencore-amrwb-dev librtmp-dev libsdl1.2-dev libsdl2-dev libtheora-dev libtool libvdpau-dev vdpauinfo libvdpau-va-gl1 libvorbis-dev libfdk-aac-dev libvpx-dev libx264-dev libx11-dev libxext-dev libxfixes-dev libx11-xcb-dev libdrm-dev libxcb-dri3-dev libxcb-present-dev libpciaccess-dev frei0r-plugins-dev texi2html yasm zlib1g-dev nasm libxml2-dev pkg-config vainfo qttools5-dev qttools5-dev-tools libqt5svg5-dev ladspa-sdk git cmake libsndfile1-dev libsamplerate-ocaml-dev libjack-jackd2-dev liblilv-dev libiec61883-dev libavc1394-dev libass-dev libbluray-dev libbs2b-dev libcodec2-dev libdc1394-22-dev libgme-dev libgsm1-dev libopenjp2-7-dev libopenmpt-dev libopus-dev librsvg2-dev librubberband-dev libshine-dev libsnappy-dev libsoxr-dev libssh-dev libspeex-dev libtwolame-dev libwavpack-dev libwebp-dev libx265-dev libxvidcore-dev libzmq3-dev libzvbi-dev libopenal-dev libomxil-bellagio-dev libcdio-dev libcdparanoia-dev libcdio-paranoia-dev libsdl2-dev opencl-headers ocl-icd-dev ocl-icd-opencl-dev vdpau-driver-all libvdpau-dev libvdpau-va-gl1 meson autoconf automake unzip wget doxygen libcurl4-openssl-dev libdrm-dev xorg xorg-dev openbox libx11-dev libgl1-mesa-glx libgl1-mesa-dev qt5-default libvtk6-dev zlib1g-dev libjpeg-dev libwebp-dev libpng-dev libtiff5-dev libopenexr-dev libgdal-dev libxvidcore-dev libopencore-amrnb-dev libopencore-amrwb-dev libv4l-dev libxine2-dev libtbb-dev libeigen3-dev python-dev python-tk pylint python-numpy python3-pip python3-dev python3-tk pylint3 python3-numpy python3-opencv python3-scipy python3-pil python3-flask python3-wheel flake8 libpython-all-dev libpython3-all-dev ant default-jdk libchromaprint-dev libgtkglext1 libgtkglext1-dev liblog4cpp5-dev libdevil-dev liblivemedia-dev v4l-utils libcpprest-dev libgflags-dev libngraph0-dev libatlas3-base libatlas-base-dev libblas-dev liblapack-dev liblapacke-dev libgoogle-glog-dev curl libtbb2 libtbb-dev libjpeg-dev libpng-dev libtiff-dev libdc1394-22-dev libvtk5-qt4-dev libqt4-dev libqt4-opengl-dev libgtkglext1 libgtkglext1-dev libmysqlclient-dev gcc-8 g++-8
目前错误是：
Reading package lists... Done Building dependency tree Reading state information... Done Note, selecting 'python-dev-is-python2' instead of 'python-dev' Note, selecting 'pylint' instead of 'pylint3' E: Unable to locate package libvtk5-qt4-dev
答案1
这是 GPG 错误。当您尝试安装来自未知来源的软件包时，会发生此错误。当您收到此错误时，您将无法更新您的存储库。要修复此错误，您应该导入公共 GPG 密钥。
错误描述中提到了该问题：
“由于公钥不可用，无法验证以下签名：NO_PUBKEY A5D32F012649A5A9”
尝试：
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys A5D32F012649A5A9
sudo apt-get 更新