R3.5 and R4.0.1 on RHEL 7, GCC 7.2, ignoring environment value of R_HOME, segfault w gcc 11.2

[LinuxPersonEC]

On RHEL 7.5 with Bright Cluster Manager, which allows loading of different versions of packages via a module load command, and rstan fails to compile with R3.5.1 and R4.0.1. but does compile with R4.1

R/3.5.1 and gcc/7.2.0 /path/to/3.5/RcppEigen/include/Eigen/src/Core/CoreEvaluators.h:989:54: warning: ignoring attributes on template argument ‘Eigen::internal::packet_traits::type’ {aka ‘__m256d’} [-Wignored-attributes] 989 | PacketAlignment = unpacket_traits<PacketScalar>::alignment, | ^~~~~~~~~ g++: warning: WARNING:: linker input file unused because linking not done g++: error: WARNING:: linker input file not found: No such file or directory g++: warning: ignoring: linker input file unused because linking not done g++: error: ignoring: linker input file not found: No such file or directory g++: warning: environment: linker input file unused because linking not done g++: error: environment: linker input file not found: No such file or directory g++: warning: value: linker input file unused because linking not done g++: error: value: linker input file not found: No such file or directory g++: warning: of: linker input file unused because linking not done g++: error: of: linker input file not found: No such file or directory g++: warning: R_HOME: linker input file unused because linking not done g++: error: R_HOME: linker input file not found: No such file or directory make: *** [chains.o] Error 1

R/4.0.1 and gcc/7.2.0 Error: C++14 standard requested but CXX14 is not defined

R/4.0.1 and gcc/11.2.0

** testing if installed package can be loaded from temporary location
sh: line 1: 293237 Segmentation fault      R_TESTS= '/path/to/R/bin/R' --no-save --no-restore --no-echo 2>&1 < '/tmp/RtmpZdP7sv/file47397117b9cf'

 *** caught segfault ***
address 0x20, cause 'memory not mapped'

Traceback:
 1: Module(module, mustStart = TRUE, where = env)
 2: doTryCatch(return(expr), name, parentenv, handler)
 3: tryCatchOne(expr, names, parentenv, handlers[[1L]])
 4: tryCatchList(expr, classes, parentenv, handlers)
 5: tryCatch(Module(module, mustStart = TRUE, where = env), error = function(e) e)
 6: Rcpp::loadModule("class_model_base", what = TRUE)
 7: fun(libname, pkgname)
 8: doTryCatch(return(expr), name, parentenv, handler)
 9: tryCatchOne(expr, names, parentenv, handlers[[1L]])
10: tryCatchList(expr, classes, parentenv, handlers)
11: tryCatch(fun(libname, pkgname), error = identity)
12: runHook(".onLoad", env, package.lib, package)
13: loadNamespace(package, lib.loc)
14: doTryCatch(return(expr), name, parentenv, handler)
15: tryCatchOne(expr, names, parentenv, handlers[[1L]])
16: tryCatchList(expr, classes, parentenv, handlers)
17: tryCatch({    attr(package, "LibPath") <- which.lib.loc    ns <- loadNamespace(package, lib.loc)    env <- attachNamespace(ns, pos = pos, deps, exclude, include.only)}, error = function(e) {    P <- if (!is.null(cc <- conditionCall(e)))         paste(" in", deparse(cc)[1L])    else ""    msg <- gettextf("package or namespace load failed for %s%s:\n %s",         sQuote(package), P, conditionMessage(e))    if (logical.return)         message(paste("Error:", msg), domain = NA)    else stop(msg, call. = FALSE, domain = NA)})
18: library(pkg_name, lib.loc = lib, character.only = TRUE, logical.return = TRUE)
19: withCallingHandlers(expr, packageStartupMessage = function(c) tryInvokeRestart("muffleMessage"))
20: suppressPackageStartupMessages(library(pkg_name, lib.loc = lib,     character.only = TRUE, logical.return = TRUE))
21: doTryCatch(return(expr), name, parentenv, handler)
22: tryCatchOne(expr, names, parentenv, handlers[[1L]])
23: tryCatchList(expr, classes, parentenv, handlers)
24: tryCatch(expr, error = function(e) {    call <- conditionCall(e)    if (!is.null(call)) {        if (identical(call[[1L]], quote(doTryCatch)))             call <- sys.call(-4L)        dcall <- deparse(call)[1L]        prefix <- paste("Error in", dcall, ": ")        LONG <- 75L        sm <- strsplit(conditionMessage(e), "\n")[[1L]]        w <- 14L + nchar(dcall, type = "w") + nchar(sm[1L], type = "w")        if (is.na(w))             w <- 14L + nchar(dcall, type = "b") + nchar(sm[1L],                 type = "b")        if (w > LONG)             prefix <- paste0(prefix, "\n  ")    }    else prefix <- "Error : "    msg <- paste0(prefix, conditionMessage(e), "\n")    .Internal(seterrmessage(msg[1L]))    if (!silent && isTRUE(getOption("show.error.messages"))) {        cat(msg, file = outFile)        .Internal(printDeferredWarnings())    }    invisible(structure(msg, class = "try-error", condition = e))})
25: try(suppressPackageStartupMessages(library(pkg_name, lib.loc = lib,     character.only = TRUE, logical.return = TRUE)))
26: tools:::.test_load_package("rstan", "/moto/home/rk3199/R/x86_64-pc-linux-gnu-library/4.0/00LOCK-rstan/00new")
An irrecoverable exception occurred. R is aborting now ...
ERROR: loading failed

R4.1:

> library(rstan)
Loading required package: StanHeaders
Loading required package: ggplot2
rstan (Version 2.21.3, GitRev: 2e1f913d3ca3)
For execution on a local, multicore CPU with excess RAM we recommend calling
options(mc.cores = parallel::detectCores()).
To avoid recompilation of unchanged Stan programs, we recommend calling
rstan_options(auto_write = TRUE)

.R/Makevars

CXX14FLAGS=-O3 -march=native -mtune=native -fPIC
CXX14FLAGS+= -Wno-unused-variable -Wno-unused-function
CXX14 = g++ -std=c++1y

Is there any option I'm missing here to get this running on R3.5?

Edit: Update, using GCC11.2 and installing the 'Rcpp' package I was able to get rstan to work on R4.0.1. Any work arounds for R 3.5?