Use POSIX syntax

Makefile

@@ -51,7 +51,7 @@ test: all
 
 # Auto-detection
 pre:
-	@which fstar.exe >/dev/null 2>&1 || [ -x $(FSTAR_HOME)/bin/fstar.exe ] || \
+	@command -v fstar.exe >/dev/null 2>&1 || [ -x $(FSTAR_HOME)/bin/fstar.exe ] || \
 	  { echo "Didn't find fstar.exe in the path or in FSTAR_HOME (which is: $(FSTAR_HOME))"; exit 1; }
 	@ocamlfind query fstarlib >/dev/null 2>&1 || [ -f $(FSTAR_HOME)/bin/fstarlib/fstarlib.cmxa ] || \
 	  { echo "Didn't find fstarlib via ocamlfind or in FSTAR_HOME (which is: $(FSTAR_HOME)); run $(MAKE) -C $(FSTAR_HOME)/ulib/ml"; exit 1; }

build_local.sh

@@ -1,15 +1,15 @@
-#!/usr/bin/env bash
+#!/bin/sh
 set -e
 
 # Look for config.json file
 FILE=".docker/build/config.json"
-if [[ ! -f $FILE ]]; then
+if [ ! -f $FILE ]; then
    echo "File $FILE does not exist."
 fi
 
 # In case you want to build windows, change agentOS here to windows-nt if OSTYPE is not working
 agentOS=linux
-if [[ "$OSTYPE" == "cygwin" ]]; then
+if [ "$OSTYPE" == "cygwin" ]; then
     agentOS=linux #windows-nt
 fi
 
@@ -32,7 +32,7 @@ REQUESTEDBRANCHNAME=$(jq -c -r ".BranchName" "$FILE")
 REQUESTEDCOMMITID=$(jq -c -r ".BaseContainerImageTagOrCommitId" "$FILE")
 COMMITURL=$(jq -c -r ".GithubCommitUrl" "$FILE")/$REQUESTEDBRANCHNAME
 
-if [[ $(jq -c -r ".BaseContainerImageTagOrCommitId" "$FILE") -ne "latest" ]]; then
+if [ "$(jq -c -r '.BaseContainerImageTagOrCommitId' "$FILE")" -ne "latest" ]; then
     COMMITURL=$(jq -c -r ".GithubCommitUrl" "$FILE")/$REQUESTEDCOMMITID
 fi
 

kremlib/Makefile

@@ -47,7 +47,7 @@ ROOTS = $(wildcard *.fst) $(wildcard *.fsti) $(wildcard ../runtime/*.fst) \
 clean: clean-c
 	rm -rf *.checked *.source .depend
 
-SHELL:=$(shell which bash)
+SHELL:=$(shell command -v sh || echo /bin/sh)
 
 clean-c:
 	rm -rf dist out extract-all */*.o

src/Driver.ml

@@ -221,7 +221,7 @@ let detect_fstar () =
     fstar_home := r;
     fstar := r ^^ "bin" ^^ "fstar.exe"
   with Not_found -> try
-    fstar := read_one_line "which" [| "fstar.exe" |];
+    fstar := read_one_line "sh" [| "-c"; "command -v fstar.exe" |];
     fstar_home := d (d !fstar);
     if not !Options.silent then
       KPrint.bprintf "FSTAR_HOME is %s (via fstar.exe in PATH)\n" !fstar_home