Problem

check_ded2('CO2','')

Error in grep(element, formula_elements) : invalid 'pattern' argument

Session Info (just in case):

sessionInfo()

R version 3.6.3 (2020-02-29)
Platform: x86_64-unknown-linux-gnu (64-bit)
Running under: Pop!_OS 20.04 LTS

Matrix products: default
BLAS/LAPACK: /gnu/store/vax1vsg3ivf0r7j7n2xkbi1z3r0504l9-openblas-0.3.7/lib/libopenblasp-r0.3.7.so

locale:
[1] LC_CTYPE=en_GB.UTF-8 LC_NUMERIC=C
[3] LC_TIME=en_GB.UTF-8 LC_COLLATE=en_GB.UTF-8
[5] LC_MONETARY=de_DE.UTF-8 LC_MESSAGES=en_GB.UTF-8
[7] LC_PAPER=de_DE.UTF-8 LC_NAME=en_GB.UTF-8
[9] LC_ADDRESS=en_GB.UTF-8 LC_TELEPHONE=en_GB.UTF-8
[11] LC_MEASUREMENT=de_DE.UTF-8 LC_IDENTIFICATION=en_GB.UTF-8

attached base packages:
[1] grid stats graphics grDevices utils datasets methods
[8] base

other attached packages:
[1] ReSOLUTION_0.1.8 nontarget_2.1 mgcv_1.8-31 nlme_3.1-145
[5] nontargetData_1.1 mzR_2.20.0 readxl_1.3.1 OrgMassSpecR_0.5-3
[9] RChemMass_0.1.23 RCurl_1.95-0.1.2 bitops_1.0-6 rjson_0.2.20
[13] rsvg_1.3 curl_4.3 rcdk_3.4.3 rcdklibs_2.0
[17] rJava_0.9-12 RMassBank_2.14.1 Rcpp_1.0.4 enviPat_2.4

loaded via a namespace (and not attached):
[1] ProtGenerics_1.18.0 doParallel_1.0.15 MSnbase_2.12.0
[4] tools_3.6.3 R6_2.4.1 affyio_1.56.0
[7] BiocGenerics_0.32.0 colorspace_1.4-1 tidyselect_1.0.0
[10] compiler_3.6.3 preprocessCore_1.48.0 cli_2.0.2
[13] Biobase_2.46.0 scales_1.1.0 affy_1.64.0
[16] digest_0.6.25 pkgconfig_2.0.3 htmltools_0.4.0
[19] fastmap_1.0.1 itertools_0.1-3 limma_3.42.2
[22] rlang_0.4.5 impute_1.60.0 shiny_1.4.0.2
[25] mzID_1.24.0 BiocParallel_1.20.1 dplyr_0.8.5
[28] magrittr_1.5 MALDIquant_1.19.3 Matrix_1.2-18
[31] munsell_0.5.0 S4Vectors_0.24.3 fansi_0.4.1
[34] lifecycle_0.2.0 vsn_3.54.0 yaml_2.2.1
[37] MASS_7.3-51.5 zlibbioc_1.32.0 plyr_1.8.6
[40] parallel_3.6.3 promises_1.1.0 crayon_1.3.4
[43] lattice_0.20-40 splines_3.6.3 pillar_1.4.3
[46] shinyscreen_0.9.0 codetools_0.2-16 stats4_3.6.3
[49] XML_3.99-0.3 glue_1.3.2 pcaMethods_1.78.0
[52] data.table_1.12.8 BiocManager_1.30.10 png_0.1-7
[55] vctrs_0.2.4 httpuv_1.5.2 foreach_1.5.0
[58] cellranger_1.1.0 gtable_0.3.0 purrr_0.3.3
[61] assertthat_0.2.1 ggplot2_3.3.0 mime_0.9
[64] xtable_1.8-4 later_1.0.0 ncdf4_1.17
[67] tibble_3.0.0 iterators_1.0.12 fingerprint_3.5.7
[70] IRanges_2.20.2 ellipsis_0.3.0