title: R/ RStudio - install devtools fails?
body: <p>I am trying to install <code>devtools</code> in my RStudio. But I get tons of errors:</p>
  
  <pre><code>* installing *source* package ‘curl’ ...
  ** package ‘curl’ successfully unpacked and MD5 sums checked
  Package libcurl was not found in the pkg-config search path.
  Perhaps you should add the directory containing `libcurl.pc'
  to the PKG_CONFIG_PATH environment variable
  No package 'libcurl' found
  Package libcurl was not found in the pkg-config search path.
  Perhaps you should add the directory containing `libcurl.pc'
  to the PKG_CONFIG_PATH environment variable
  No package 'libcurl' found
  Using PKG_CFLAGS=
  Using PKG_LIBS=-lcurl
  ------------------------- ANTICONF ERROR ---------------------------
  Configuration failed because libcurl was not found. Try installing:
   * deb: libcurl4-openssl-dev (Debian, Ubuntu, etc)
   * rpm: libcurl-devel (Fedora, CentOS, RHEL)
   * csw: libcurl_dev (Solaris)
  If libcurl is already installed, check that 'pkg-config' is in your
  PATH and PKG_CONFIG_PATH contains a libcurl.pc file. If pkg-config
  is unavailable you can set INCLUDE_DIR and LIB_DIR manually via:
  R CMD INSTALL --configure-vars='INCLUDE_DIR=... LIB_DIR=...'
  --------------------------------------------------------------------
  ERROR: configuration failed for package ‘curl’
  * removing ‘/home/lau/R/x86_64-pc-linux-gnu-library/3.4/curl’
  Warning in install.packages :
    installation of package ‘curl’ had non-zero exit status
  * installing *source* package ‘openssl’ ...
  ** package ‘openssl’ successfully unpacked and MD5 sums checked
  Using PKG_CFLAGS=
  Using PKG_LIBS=-lssl -lcrypto
  ------------------------- ANTICONF ERROR ---------------------------
  Configuration failed because openssl was not found. Try installing:
   * deb: libssl-dev (Debian, Ubuntu, etc)
   * rpm: openssl-devel (Fedora, CentOS, RHEL)
   * csw: libssl_dev (Solaris)
   * brew: openssl@1.1 (Mac OSX)
  If openssl is already installed, check that 'pkg-config' is in your
  PATH and PKG_CONFIG_PATH contains a openssl.pc file. If pkg-config
  is unavailable you can set INCLUDE_DIR and LIB_DIR manually via:
  R CMD INSTALL --configure-vars='INCLUDE_DIR=... LIB_DIR=...'
  --------------------------------------------------------------------
  ERROR: configuration failed for package ‘openssl’
  * removing ‘/home/lau/R/x86_64-pc-linux-gnu-library/3.4/openssl’
  Warning in install.packages :
    installation of package ‘openssl’ had non-zero exit status
  * installing *source* package ‘git2r’ ...
  ** package ‘git2r’ successfully unpacked and MD5 sums checked
  checking build system type... x86_64-unknown-linux-gnu
  checking host system type... x86_64-unknown-linux-gnu
  checking for gcc... gcc
  checking whether the C compiler works... yes
  checking for C compiler default output file name... a.out
  checking for suffix of executables... 
  checking whether we are cross compiling... no
  checking for suffix of object files... o
  checking whether we are using the GNU C compiler... yes
  checking whether gcc accepts -g... yes
  checking for gcc option to accept ISO C89... none needed
  checking for library containing inflate... -lz
  checking for pkg-config... /usr/bin/pkg-config
  checking pkg-config is at least version 0.9.0... yes
  checking for libssl... no
  configure: WARNING: "pkg-config failed to find libssl."
  checking for library containing EVP_EncryptInit... no
  configure: error: in `/tmp/RtmpWzaIce/R.INSTALL67fa335a4d20/git2r':
  configure: error: 
    ---------------------------------------------
     The OpenSSL library that is required to
     build git2r was not found.
  
     Please install:
       libssl-dev    (package on e.g. Debian and Ubuntu)
       openssl-devel (package on e.g. Fedora, CentOS and RHEL)
       openssl       (Homebrew package on OS X)
     and try again.
  
     If the OpenSSL library is installed on
     your system but the git2r configuration
     is unable to find it, you can specify
     the include and lib path to OpenSSL with:
     R CMD INSTALL --configure-args='--with-libssl-include=INCLUDE_PATH --with-libssl-lib=LIB_PATH' git2r
    ---------------------------------------------
  See `config.log' for more details
  ERROR: configuration failed for package ‘git2r’
  * removing ‘/home/lau/R/x86_64-pc-linux-gnu-library/3.4/git2r’
  Warning in install.packages :
    installation of package ‘git2r’ had non-zero exit status
  ERROR: dependencies ‘curl’, ‘openssl’ are not available for package ‘httr’
  * removing ‘/home/lau/R/x86_64-pc-linux-gnu-library/3.4/httr’
  Warning in install.packages :
    installation of package ‘httr’ had non-zero exit status
  ERROR: dependencies ‘httr’, ‘git2r’ are not available for package ‘devtools’
  * removing ‘/home/lau/R/x86_64-pc-linux-gnu-library/3.4/devtools’
  Warning in install.packages :
    installation of package ‘devtools’ had non-zero exit status
  
  The downloaded source packages are in
      ‘/tmp/RtmpzxXdFr/downloaded_packages’
  </code></pre>
  
  <p>So I tried to install <code>libcurl</code>:</p>
  
  <pre><code>&gt; install.packages("libcurl")
  Installing package into ‘/home/lau/R/x86_64-pc-linux-gnu-library/3.4’
  (as ‘lib’ is unspecified)
  Warning in install.packages :
    package ‘libcurl’ is not available (for R version 3.4.0)
  &gt; install.packages("curl")
  </code></pre>
  
  <p>I'm on Ubuntu 17.04. And R 3.4.</p>
  
  <p>Any ideas how I can fix this?</p>