Imagemagick-7.0.8 needs to link against libltdl. Otherwise, the build will fail with:
```
2 errors found in build log:
503 checking for libltdl...
504 checking ltdl.h usability... no
505 checking ltdl.h presence... no
506 checking for ltdl.h... no
507 checking for lt_dlinit in -lltdl... no
508 checking if libltdl package is complete... no
>> 509 configure: error: in `/tmp/gpjohnsn/spack-stage/spack-stage-imagemagick-7.0.8-7-4y44gaklhhciiwjzhfpxjfwdj5q
ltjp3/spack-src':
>> 510 configure: error: libltdl is required for modules and OpenCL builds
511 See `config.log' for more details
```
* add version 3.8.2 to r-gtools
* Improve formatting of description
In case the list gets formatted as a non-list:
- added semicolons to end of list items
- replaced dashes with [#]
* add version 1.30 to r-knitr
* Fix version constraints
- r-digest
- r-formatr
The version constraints on those packages should actually be in the `when`
clause.
'date' is a C++ header library offering extensive date and time
functionality for the C++11, C++14 and C++17 standards written by Howard
Hinnant and released under the MIT license. A slightly modified version
has been accepted (along with 'tz.h') as part of C++20. This package
regroups all header files from the upstream repository by Howard Hinnant
so that other R packages can use them in their C++ code. At present, few
of the types have explicit 'Rcpp' wrapper though these may be added as
needed.
Designed to ease the application and comparison of multiple hypothesis
testing procedures for FWER, gFWER, FDR and FDX. Methods are
standardized and usable by the accompanying 'mutossGUI'.
Utility functions that enhance the 'parallel' package and support the
built-in parallel backends of the 'future' package. For example,
availableCores() gives the number of CPU cores available to your R
process as given by the operating system, 'cgroups' and Linux
containers, R options, and environment variables, including those set by
job schedulers on high-performance compute clusters. If none is set, it
will fall back to parallel::detectCores(). Another example is
makeClusterPSOCK(), which is backward compatible with
parallel::makePSOCKcluster() while doing a better job in setting up
remote cluster workers without the need for configuring the firewall to
do port-forwarding to your local computer.
Contains third-party map tile provider information from 'Leaflet.js',
<https://github.com/leaflet-extras/leaflet-providers>, to be used with
the 'leaflet' R package. Additionally, 'leaflet.providers' enables users
to retrieve up-to-date provider information between package updates.
