Package nss was not found in the pkg-config search path.

qmake编译过程中出错：

ERROR at //build/config/linux/pkg_config.gni:103:17: Script returned non-zero exit code.
    pkgresult = exec_script(pkg_config_script, args, "value")
                ^----------
Current dir: /home/mcj/qt-everywhere-src-5.15.2/qtwebengine/src/pdf/release/
Command: /usr/bin/python2 /home/mcj/qt-everywhere-src-5.15.2/qtwebengine/src/3rdparty/chromium/build/config/linux/pkg-config.py -p pkg-config nss -v -lssl3
Returned 1.
stderr:

Package nss was not found in the pkg-config search path.
Perhaps you should add the directory containing `nss.pc'
to the PKG_CONFIG_PATH environment variable
No package 'nss' found
Could not run pkg-config.

See //build/config/linux/nss/BUILD.gn:15:3: whence it was called.
  pkg_config("system_nss_no_ssl_config") {
  ^---------------------------------------
See //crypto/BUILD.gn:214:25: which caused the file to be included.
    public_configs += [ "//build/config/linux/nss:system_nss_no_ssl_config" ]
                        ^--------------------------------------------------
Project ERROR: GN run error!
Makefile:65: recipe for target 'sub-gn_run-pro-make_first' failed

解决方案：

sudo apt-get install libnss3-dev