就在最近，我不得不备份一些应用程序文件，但它们却停止工作了，我不知道为什么。例如，在尝试启动时nautilus-dropbox，megasync我收到与 Qt 库相关的错误。请参阅下面的日志。
Dropbox
sudo dropbox start
[sudo] password for b-fg:
Starting Dropbox...dropbox: locating interpreter
dropbox: logging to /tmp/dropbox-antifreeze-gsXuyT
dropbox: initializing
dropbox: initializing python 3.5.4
dropbox: setting program path '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/dropbox'
dropbox: setting home path '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90'
dropbox: setting python path '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90:/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/python-packages-35.zip'
dropbox: python initialized
dropbox: running dropbox
dropbox: setting args
dropbox: applying overrides
dropbox: running main script
dropbox: load fq extension '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/cryptography.hazmat.bindings._constant_time.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/cryptography.hazmat.bindings._openssl.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/cryptography.hazmat.bindings._padding.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/psutil._psutil_linux.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/psutil._psutil_posix.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/linuxffi.pthread._linuxffi_pthread.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/linuxffi.fcntl._linuxffi_fcntl.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/linuxffi.sys.compiled._linuxffi_sys.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/tornado.speedups.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/cpuid.compiled._cpuid.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/linuxffi.resolv.compiled._linuxffi_resolv.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/posixffi.libc._posixffi_libc.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/librsyncffi.compiled._librsyncffi.cpython-35m-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/PyQt5.QtWebKit.cpython-35m-x86_64-linux-gnu.so'
Dropbox isn't running!
Done!
b-fg@IHPC:~$ dropbox: load fq extension '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/PyQt5.QtWebKit.cpython-35m-x86_64-linux-gnu.so'
bn.BUILD_KEY: Dropbox
bn.VERSION: 54.4.90
bn.DROPBOXEXT_VERSION: failed
bn.is_frozen: True
machine_id: failed
pid: 9754
ppid: 1289
ppid exe: '/lib/systemd/systemd'
uid: 0
user_info: pwd.struct_passwd(pw_name='root', pw_passwd='x', pw_uid=0, pw_gid=0, pw_gecos='root', pw_dir='/root', pw_shell='/bin/bash')
effective_user_info: pwd.struct_passwd(pw_name='root', pw_passwd='x', pw_uid=0, pw_gid=0, pw_gecos='root', pw_dir='/root', pw_shell='/bin/bash')
euid: 0
gid: 0
egid: 0
group_info: grp.struct_group(gr_name='root', gr_passwd='x', gr_gid=0, gr_mem=[])
effective_group_info: grp.struct_group(gr_name='root', gr_passwd='x', gr_gid=0, gr_mem=[])
LD_LIBRARY_PATH: None
cwd: '/home/b-fg'
real_path='/home/b-fg'
mode=0o40755 uid=1000 gid=1000
parent mode=0o40755 uid=0 gid=0
HOME: '/home/b-fg'
appdata: '/home/b-fg/.dropbox/instance1'
real_path='/home/b-fg/.dropbox/instance1'
mode=0o40700 uid=1000 gid=1000
parent mode=0o40700 uid=1000 gid=1000
dropbox_path: '/home/b-fg/Dropbox'
real_path='/home/b-fg/Dropbox'
mode=0o40700 uid=1000 gid=1000
parent mode=0o40755 uid=1000 gid=1000
sys_executable: '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/dropbox'
real_path='/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/dropbox'
mode=0o100755 uid=1000 gid=1000
parent mode=0o40755 uid=1000 gid=1000
trace.__file__: '/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/python-packages-35.zip/dropbox/client/ui/common/boot_error.pyc'
real_path='/home/b-fg/.dropbox-dist/dropbox-lnx.x86_64-54.4.90/python-packages-35.zip/dropbox/client/ui/common/boot_error.pyc'
not found
parent not found
tempdir: '/tmp'
real_path='/tmp'
mode=0o41777 uid=0 gid=0
parent mode=0o40755 uid=0 gid=0
Traceback (most recent call last):
File "dropbox/client/main.pyc", line 6689, in main_startup
File "dropbox/client/main.pyc", line 3035, in run
File "ui/common/uikit.pyc", line 744, in create_ui_kit
File "dropbox/client/ui/qt/__init__.pyc", line 34, in <module>
File "<_bootstrap_overrides>", line 162, in load_module
ImportError: /usr/lib/x86_64-linux-gnu/libxslt.so.1: symbol xmlBufContent version LIBXML2_2.9.0 not defined in file libxml2.so.2 with link time reference
Couldn't start Dropbox.
This is usually because of a permissions error. Storing your home folder on a network share can also cause an error.
Get more help at https://www.dropbox.com/c/help/permissions_error
Please check the system console for more details.
兆同步
sudo megasync
megasync: relocation error: megasync: symbol _ZN10QSslSocket13setPrivateKeyERK7QSslKey version Qt_5 not defined in file libQt5Network.so.5 with link time reference
我搜索过这个问题，并尝试了一些修复方法，比如包括以下几行，但~/.bashrc没有成功
export LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu/:$LD_LIBRARY_PATH
我认为 Qt 版本和依赖项存在冲突，但我无法确定具体是什么。重新安装应用程序或重新启动也无济于事。