Error(s) in re-building vignettes:
  ...
--- re-building ‘introduction.Rmd’ using rmarkdown
Warning in engine$weave(file, quiet = quiet, encoding = enc) :
  Pandoc (>= 1.12.3) and/or pandoc-citeproc not available. Falling back to R Markdown v1.
Installing package into '/tmp/Rtmp.Ma4qQ/RLIBS_54872d387022'
(as 'lib' is unspecified)
trying URL 'http://cran.us.r-project.org/src/contrib/devtools_2.3.2.tar.gz'
Content type 'application/x-gzip' length 373387 bytes (364 KB)
==================================================
downloaded 364 KB

* installing *source* package ‘devtools’ ...
** package ‘devtools’ successfully unpacked and MD5 sums checked
** using staged installation
** R
** inst
** byte-compile and prepare package for lazy loading
** help
*** installing help indices
*** copying figures
** building package indices
** installing vignettes
** testing if installed package can be loaded from temporary location
** testing if installed package can be loaded from final location
** testing if installed package keeps a record of temporary installation path
* DONE (devtools)

The downloaded source packages are in
	'/tmp/Rtmp.Ma4qQ/working_dir/RtmpDca4ad/downloaded_packages'
Loading required package: usethis
Downloading GitHub repo ChristineBlume/SleepCycles@HEAD
Skipping 1 packages ahead of CRAN: htmlwidgets
Installing 5 packages: zip, credentials, rappdirs, gert, usethis
Installing packages into '/tmp/Rtmp.Ma4qQ/RLIBS_54872d387022'
(as 'lib' is unspecified)
trying URL 'https://cloud.r-project.org/src/contrib/zip_2.1.1.tar.gz'
Content type 'application/x-gzip' length 112865 bytes (110 KB)
==================================================
downloaded 110 KB

trying URL 'https://cloud.r-project.org/src/contrib/credentials_1.3.0.tar.gz'
Content type 'application/x-gzip' length 230082 bytes (224 KB)
==================================================
downloaded 224 KB

trying URL 'https://cloud.r-project.org/src/contrib/rappdirs_0.3.1.tar.gz'
Content type 'application/x-gzip' length 12838 bytes (12 KB)
==================================================
downloaded 12 KB

trying URL 'https://cloud.r-project.org/src/contrib/gert_1.0.2.tar.gz'
Content type 'application/x-gzip' length 61324 bytes (59 KB)
==================================================
downloaded 59 KB

trying URL 'https://cloud.r-project.org/src/contrib/usethis_2.0.0.tar.gz'
Content type 'application/x-gzip' length 556740 bytes (543 KB)
==================================================
downloaded 543 KB

* installing *source* package ‘zip’ ...
** package ‘zip’ successfully unpacked and MD5 sums checked
** using staged installation
** libs
/home/ripley/developerstudio12.6/bin/cc -xc99 -O -xlibmieee -xlibmil -xtarget=native -xcache=generic -nofstore  miniz.c zip.c unixutils.c tools/cmdzip.c -o tools/cmdzip
miniz.c:
zip.c:
"zip.c", line 146: warning: initializer will be sign-extended: -1
"zip.c", line 240: warning: initializer will be sign-extended: -1
unixutils.c:
tools/cmdzip.c:
/home/ripley/developerstudio12.6/bin/cc -xc99 -O -xlibmieee -xlibmil -xtarget=native -xcache=generic -nofstore  miniz.c zip.c unixutils.c tools/cmdunzip.c -o tools/cmdunzip
miniz.c:
zip.c:
"zip.c", line 146: warning: initializer will be sign-extended: -1
"zip.c", line 240: warning: initializer will be sign-extended: -1
unixutils.c:
tools/cmdunzip.c:
/home/ripley/developerstudio12.6/bin/cc -xc99 -I"/home/ripley/R/cc/include" -DNDEBUG   -I/usr/local/include  -KPIC  -O -xlibmieee -xlibmil -xtarget=native -xcache=generic -nofstore  -c init.c -o init.o
/home/ripley/developerstudio12.6/bin/cc -xc99 -I"/home/ripley/R/cc/include" -DNDEBUG   -I/usr/local/include  -KPIC  -O -xlibmieee -xlibmil -xtarget=native -xcache=generic -nofstore  -c miniz.c -o miniz.o
/home/ripley/developerstudio12.6/bin/cc -xc99 -I"/home/ripley/R/cc/include" -DNDEBUG   -I/usr/local/include  -KPIC  -O -xlibmieee -xlibmil -xtarget=native -xcache=generic -nofstore  -c rzip.c -o rzip.o
/home/ripley/developerstudio12.6/bin/cc -xc99 -I"/home/ripley/R/cc/include" -DNDEBUG   -I/usr/local/include  -KPIC  -O -xlibmieee -xlibmil -xtarget=native -xcache=generic -nofstore  -c zip.c -o zip.o
"zip.c", line 146: warning: initializer will be sign-extended: -1
"zip.c", line 240: warning: initializer will be sign-extended: -1
/home/ripley/developerstudio12.6/bin/cc -xc99 -I"/home/ripley/R/cc/include" -DNDEBUG   -I/usr/local/include  -KPIC  -O -xlibmieee -xlibmil -xtarget=native -xcache=generic -nofstore  -c unixutils.c -o unixutils.o
/home/ripley/developerstudio12.6/bin/cc -xc99 -G -L/usr/local/lib -o zip.so init.o miniz.o rzip.o zip.o unixutils.o
installing via 'install.libs.R' to /tmp/Rtmp.Ma4qQ/RLIBS_54872d387022/00LOCK-zip/00new/zip
** R
** inst
** byte-compile and prepare package for lazy loading
** help
*** installing help indices
** building package indices
** testing if installed package can be loaded from temporary location
** checking absolute paths in shared objects and dynamic libraries
** testing if installed package can be loaded from final location
** testing if installed package keeps a record of temporary installation path
* DONE (zip)
* installing *source* package ‘credentials’ ...
** package ‘credentials’ successfully unpacked and MD5 sums checked
** using staged installation
** R
** inst
** byte-compile and prepare package for lazy loading
** help
*** installing help indices
** building package indices
** installing vignettes
** testing if installed package can be loaded from temporary location
Could not read ssh config. Using default settings.
** testing if installed package can be loaded from final location
Could not read ssh config. Using default settings.
** testing if installed package keeps a record of temporary installation path
* DONE (credentials)
* installing *source* package ‘rappdirs’ ...
** package ‘rappdirs’ successfully unpacked and MD5 sums checked
** using staged installation
** libs
/home/ripley/developerstudio12.6/bin/cc -xc99 -I"/home/ripley/R/cc/include" -DNDEBUG   -I/usr/local/include  -KPIC  -O -xlibmieee -xlibmil -xtarget=native -xcache=generic -nofstore  -c win-path.c -o win-path.o
/home/ripley/developerstudio12.6/bin/cc -xc99 -G -L/usr/local/lib -o rappdirs.so win-path.o
installing to /tmp/Rtmp.Ma4qQ/RLIBS_54872d387022/00LOCK-rappdirs/00new/rappdirs/libs
** R
** byte-compile and prepare package for lazy loading
** help
*** installing help indices
** building package indices
** testing if installed package can be loaded from temporary location
** checking absolute paths in shared objects and dynamic libraries
** testing if installed package can be loaded from final location
** testing if installed package keeps a record of temporary installation path
* DONE (rappdirs)
* installing *source* package ‘gert’ ...
** package ‘gert’ successfully unpacked and MD5 sums checked
** using staged installation
Using PKG_CFLAGS=
Using PKG_LIBS=-lgit2
----------------------------- ANTICONF -------------------------------
Configuration failed to find libgit2 library. Try installing:
 * brew: libgit2 (MacOS)
 * deb: libgit2-dev (Debian, Ubuntu, etc)
 * rpm: libgit2-devel (Fedora, CentOS, RHEL)
If libgit2 is already installed, check that 'pkg-config' is in your
PATH and PKG_CONFIG_PATH contains a libgit2.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 MESSAGE] ---------------------------
cc: Warning: Option -xc passed to ld, if ld is invoked, ignored otherwise
"<stdin>", line 1: cannot find include file: <git2.h>
cc: acomp failed for -
----------------------------------------------------------------------
ERROR: configuration failed for package ‘gert’
* removing ‘/tmp/Rtmp.Ma4qQ/RLIBS_54872d387022/gert’
Warning in i.p(...) :
  installation of package 'gert' had non-zero exit status
ERROR: dependency ‘gert’ is not available for package ‘usethis’
* removing ‘/tmp/Rtmp.Ma4qQ/RLIBS_54872d387022/usethis’
Warning in i.p(...) :
  installation of package 'usethis' had non-zero exit status

The downloaded source packages are in
	'/tmp/Rtmp.Ma4qQ/working_dir/RtmpDca4ad/downloaded_packages'
Quitting from lines 51-58 (introduction.Rmd) 
Error: processing vignette 'introduction.Rmd' failed with diagnostics:
Failed to install 'SleepCycles' from GitHub:
  System command 'R' failed, exit status: 1, stdout + stderr:
E> * checking for file ‘/tmp/Rtmp.Ma4qQ/working_dir/RtmpDca4ad/remotes60711c571c3/ChristineBlume-SleepCycles-3f8f61f/DESCRIPTION’ ... OK
E> * preparing ‘SleepCycles’:
E> * checking DESCRIPTION meta-information ... OK
E> * installing the package to process help pages
E>       -----------------------------------
E> * installing *source* package ‘SleepCycles’ ...
E> ** using staged installation
E> ** R
E> ** data
E> *** moving datasets to lazyload DB
E> ** byte-compile and prepare package for lazy loading
E> Error in loadNamespace(j <- i[[1L]], c(lib.loc, .libPaths()), versionCheck = vI[[j]]) : 
E>   there is no package called ‘usethis’
E> Calls: <Anonymous> ... loadNamespace -> withRestarts -> withOneRestart -> doWithOneRestart
E> Execution halted
E> ERROR: lazy loading failed for package ‘SleepCycles’
E> * removing ‘/tmp/Rtmp.Ma4qQ/working_dir/RtmpZ9aGSB/Rinst376447e73fb0/SleepCycles’
E>       -----------------------------------
E> ERROR: package installation failed
--- failed re-building ‘introduction.Rmd’

SUMMARY: processing the following file failed:
  ‘introduction.Rmd’

Error: Vignette re-building failed.
Execution halted