[R-pkg-devel] can't reproduce cran-pretest error

Dear list,

I'm having trouble reproducing errors from CRAN's pretests.

I have a package on CRAN called epanet2toolkit that provides R bindings
to a legacy simulation engine written in C.  So far I've released two
versions
to CRAN without trouble.  Now I'm making a third release, principally to
include
a citation for the package, but also to clean up warnings raised by new
compilers.

My latest submission fails the CRAN pretests for Debian with errors in the
examples and tests:
https://win-builder.r-project.org/incoming_pretest/
epanet2toolkit_0.3.0_20180726_102947/Debian/00check.log

For what it's worth, the package checks fine under R-3.4.4, R-3.5.0 and
R-devel
r74997 (2018-07-21) and r74923 (2018-06-20).

However, when I run the debian-r-devel checks locally (albeit in Docker) I
get
a couple of warnings, but no errors. Since I can't reproduce the error, it's
difficult to fix. See below the relevant lines of 00check.log:

* using log directory ?/pkg/epanet2toolkit.Rcheck?
* using R Under development (unstable) (2018-07-25 r75006)
* using platform: x86_64-pc-linux-gnu (64-bit)
* using session charset: UTF-8
* using option ?--as-cran?
* checking for file ?epanet2toolkit/DESCRIPTION? ... OK
* checking extension type ... Package
...
* checking whether package ?epanet2toolkit? can be installed ... WARNING
Found the following significant warnings:
   text.h:421:9: warning: ?        Kw        Kw      /d? directive writing
30 bytes into a region of size between 23 and 278 [-Wformat-overflow=]
See ?/pkg/epanet2toolkit.Rcheck/00install.out? for details.
...
* checking compilation flags used ... WARNING
Compilation used the following non-portable flag(s):
   ?-Wdate-time? ?-Werror=format-security? ?-Wformat?

* checking compiled code ... OK
* checking examples ... OK
* checking for unstated dependencies in ?tests? ... OK
* checking tests ... OK
   Running ?testthat.r?
* checking PDF version of manual ... OK
* DONE
Status: 2 WARNINGs, 1 NOTE


Thanks in advance for any insights.

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