title: Trouble downloading {data.table} package
body: <p>I initially downloaded the data.table package from CRAN using:</p>
  
  <pre><code>install.packages()
  </code></pre>
  
  <p>It downloaded version 1.9.4, after hitting a few speed bumps and going through this website I figured I had to download the latest version from github. In order to do that I tried to download to "devtools" but I was unsuccessful. Following is the error I got:</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/trader/R/x86_64-pc-linux-gnu-library/3.2/curl’
  Warning in install.packages :
    installation of package ‘curl’ had non-zero exit status
  * installing *source* package ‘RCurl’ ...
  ** package ‘RCurl’ successfully unpacked and MD5 sums checked
  checking for curl-config... no
  Cannot find curl-config
  ERROR: configuration failed for package ‘RCurl’
  * removing ‘/home/trader/R/x86_64-pc-linux-gnu-library/3.2/RCurl’
  Warning in install.packages :
    installation of package ‘RCurl’ had non-zero exit status
  ERROR: dependency ‘curl’ is not available for package ‘httr’
  * removing ‘/home/trader/R/x86_64-pc-linux-gnu-library/3.2/httr’
  Warning in install.packages :
    installation of package ‘httr’ had non-zero exit status
  ERROR: dependency ‘curl’ is not available for package ‘rversions’
  * removing ‘/home/trader/R/x86_64-pc-linux-gnu-library/3.2/rversions’
  Warning in install.packages :
    installation of package ‘rversions’ had non-zero exit status
  ERROR: dependencies ‘httr’, ‘RCurl’, ‘rversions’ are not available for package ‘devtools’
  * removing ‘/home/trader/R/x86_64-pc-linux-gnu-library/3.2/devtools’
  Warning in install.packages :
    installation of package ‘devtools’ had non-zero exit status
  
  The downloaded source packages are in
      ‘/tmp/RtmpMtxhRg/downloaded_packages’
  </code></pre>
  
  <p>So I tried another approach and downloaded the .tar.gz file from <a href="https://cran.r-project.org/web/packages/data.table/index.html" rel="nofollow">https://cran.r-project.org/web/packages/data.table/index.html</a>. </p>
  
  <p>Then using:</p>
  
  <pre><code>&gt; install.packages("~/Downloads/data.table_1.9.6.tar.gz", repos = NULL, type = "source")
  </code></pre>
  
  <p>The download was successful but I got the following error when trying to load it: </p>
  
  <pre><code>&gt; library("data.table", lib.loc="~/R/x86_64-pc-linux-gnu-library/3.2")
  data.table 1.9.6  For help type ?data.table or https://github.com/Rdatatable/data.table/wiki
  The fastest way to learn (by data.table authors): https://www.datacamp.com/courses/data-analysis-the-data-table-way
  
  Attaching package: ‘data.table’
  
  The following object is masked from ‘package:xts’:
  
      last
  
  Error in fetch(key) : 
    lazy-load database '/home/trader/R/x86_64-pc-linux-gnu-library/3.2/data.table/help/data.table.rdb' is corrupt
  In addition: Warning message:
  In fetch(key) : internal error -3 in R_decompress1
  </code></pre>
  
  <p>My session info is as follows: </p>
  
  <pre><code>&gt; sessionInfo()
  R version 3.2.2 (2015-08-14)
  Platform: x86_64-pc-linux-gnu (64-bit)
  Running under: Ubuntu precise (12.04.5 LTS)
  
  locale:
   [1] LC_CTYPE=en_IN.UTF-8       LC_NUMERIC=C               LC_TIME=en_IN.UTF-8        LC_COLLATE=en_IN.UTF-8     LC_MONETARY=en_IN.UTF-8    LC_MESSAGES=en_IN.UTF-8   
   [7] LC_PAPER=en_IN.UTF-8       LC_NAME=C                  LC_ADDRESS=C               LC_TELEPHONE=C             LC_MEASUREMENT=en_IN.UTF-8 LC_IDENTIFICATION=C       
  
  attached base packages:
  [1] stats     graphics  grDevices utils     datasets  methods   base     
  
  other attached packages:
   [1] data.table_1.9.6    plyr_1.8.3          git2r_0.11.0        ISLR_1.0            bigtabulate_1.1.2   biglm_0.9-1         DBI_0.3.1           biganalytics_1.1.1 
   [9] bigmemory_4.4.6     BH_1.58.0-1         bigmemory.sri_0.1.3 highfrequency_0.4   xts_0.9-7           zoo_1.7-12         
  
  loaded via a namespace (and not attached):
  [1] Rcpp_0.12.0     lattice_0.20-33 chron_2.3-47    grid_3.2.2      magrittr_1.5    stringi_1.0-1   reshape2_1.4.1  tools_3.2.2     stringr_1.0.0 
  </code></pre>
  
  <p>I am not sure what I am supposed to do now. Can someone please help? </p>