ToneLib-Zoom_3.0-1.deb depends on libcurl3, but when I try to install it it conflicts with the following packages: apache2 apache2-bin cantor-backend-r cantor-backend-r-dbgsym cmake cryfs curl gimp-gmic gmic libapache2-mod-php7.2 libapache2-mod-php7.3 libcurl4 php7.2-curl php7.3 plasma-vault r-base-core r-base-dev r-cran-boot r-cran-class r-cran-cluster r-cran-codetools r-cran-foreign r-cran-kernsmooth r-cran-lattice r-cran-mass r-cran-matrix r-cran-mgcv r-cran-nlme r-cran-nnet r-cran-rpart r-cran-spatial r-cran-survival r-recommended virtualbox-5.2 I'd recommend compiling ToneLib against libcurl4. System: Ubuntu 18.04 LTS (64 bits)