script: Enable SC2155 rule for Gitian scripts

Also pwd command is replaced with $PWD variable everywhere for
consistency.

(cherry picked from commit bitcoin/bitcoin@61bb21b418)

contrib/gitian-descriptors/gitian-linux.yml

@@ -47,7 +47,7 @@ script: |
   export GZIP="-9n"
   export TAR_OPTIONS="--mtime="$REFERENCE_DATE\\\ $REFERENCE_TIME""
   export TZ="UTC"
-  export BUILD_DIR=$(pwd)
+  export BUILD_DIR="$PWD"
   mkdir -p ${WRAP_DIR}
   if test -n "$GBUILD_CACHE_ENABLED"; then
     export SOURCES_PATH=${GBUILD_COMMON_CACHE}
@@ -86,7 +86,7 @@ script: |
   create_per-host_faketime_wrappers "2000-01-01 12:00:00"
 
   cd zcash
-  BASEPREFIX=$(pwd)/depends
+  BASEPREFIX="${PWD}/depends"
   # Build dependencies for each host
   for i in $HOSTS; do
     make ${MAKEOPTS} -C ${BASEPREFIX} HOST="${i}"
@@ -116,7 +116,7 @@ script: |
     export PATH=${BASEPREFIX}/${i}/native/bin:${ORIGPATH}
     mkdir -p distsrc-${i}
     cd distsrc-${i}
-    INSTALLPATH=$(pwd)/installed/${DISTNAME}
+    INSTALLPATH="${PWD}/installed/${DISTNAME}"
     mkdir -p ${INSTALLPATH}
     tar --strip-components=1 -xf ../$SOURCEDIST
 

contrib/gitian-descriptors/gitian-osx-signer.yml

@@ -15,7 +15,7 @@ files:
 script: |
   WRAP_DIR=$HOME/wrapped
   mkdir -p ${WRAP_DIR}
-  export PATH=$(pwd):$PATH
+  export PATH="$PWD":$PATH
   FAKETIME_PROGS="dmg genisoimage"
 
   # Create global faketime wrappers

contrib/gitian-descriptors/gitian-osx.yml

@@ -36,7 +36,7 @@ script: |
   export GZIP="-9n"
   export TAR_OPTIONS="--mtime="$REFERENCE_DATE\\\ $REFERENCE_TIME""
   export TZ="UTC"
-  export BUILD_DIR=$(pwd)
+  export BUILD_DIR="$PWD"
   mkdir -p ${WRAP_DIR}
   if test -n "$GBUILD_CACHE_ENABLED"; then
     export SOURCES_PATH=${GBUILD_COMMON_CACHE}
@@ -77,7 +77,7 @@ script: |
   create_per-host_faketime_wrappers "2000-01-01 12:00:00"
 
   cd bitcoin
-  BASEPREFIX=$(pwd)/depends
+  BASEPREFIX="${PWD}/depends"
 
   mkdir -p ${BASEPREFIX}/SDKs
   tar -C ${BASEPREFIX}/SDKs -xf ${BUILD_DIR}/Xcode-11.3.1-11C505-extracted-SDK-with-libcxx-headers.tar.gz
@@ -112,7 +112,7 @@ script: |
     export PATH=${BASEPREFIX}/${i}/native/bin:${ORIGPATH}
     mkdir -p distsrc-${i}
     cd distsrc-${i}
-    INSTALLPATH=$(pwd)/installed/${DISTNAME}
+    INSTALLPATH="${PWD}/installed/${DISTNAME}"
     mkdir -p ${INSTALLPATH}
     tar --strip-components=1 -xf ../$SOURCEDIST
 

contrib/gitian-descriptors/gitian-win-signer.yml

@@ -15,7 +15,7 @@ files:
 - "osslsigncode-Backports-to-1.7.1.patch"
 - "bitcoin-win-unsigned.tar.gz"
 script: |
-  BUILD_DIR=$(pwd)
+  BUILD_DIR="$PWD"
   SIGDIR=${BUILD_DIR}/signature/win
   UNSIGNED_DIR=${BUILD_DIR}/unsigned
 

contrib/gitian-descriptors/gitian-win.yml

@@ -37,7 +37,7 @@ script: |
   export GZIP="-9n"
   export TAR_OPTIONS="--mtime="$REFERENCE_DATE\\\ $REFERENCE_TIME""
   export TZ="UTC"
-  export BUILD_DIR=$(pwd)
+  export BUILD_DIR="$PWD"
   mkdir -p ${WRAP_DIR}
   if test -n "$GBUILD_CACHE_ENABLED"; then
     export SOURCES_PATH=${GBUILD_COMMON_CACHE}
@@ -101,7 +101,7 @@ script: |
   create_per-host_linker_wrapper "2000-01-01 12:00:00"
 
   cd bitcoin
-  BASEPREFIX=$(pwd)/depends
+  BASEPREFIX="${PWD}/depends"
   # Build dependencies for each host
   for i in $HOSTS; do
     make ${MAKEOPTS} -C ${BASEPREFIX} HOST="${i}"
@@ -134,7 +134,7 @@ script: |
     export PATH=${BASEPREFIX}/${i}/native/bin:${ORIGPATH}
     mkdir -p distsrc-${i}
     cd distsrc-${i}
-    INSTALLPATH=$(pwd)/installed/${DISTNAME}
+    INSTALLPATH="${PWD}/installed/${DISTNAME}"
     mkdir -p ${INSTALLPATH}
     tar --strip-components=1 -xf ../$SOURCEDIST
 

test/lint/lint-shell.sh

@@ -29,7 +29,6 @@ disabled_gitian=(
     SC2043 # This loop will only ever run once for a constant value. Did you perhaps mean to loop over dir/*, $var or $(cmd)?
     SC2094 # Make sure not to read and write the same file in the same pipeline.
     SC2129 # Consider using { cmd1; cmd2; } >> file instead of individual redirects.
-    SC2155 # Declare and assign separately to avoid masking return values.
     SC2164 # Use 'cd ... || exit' or 'cd ... || return' in case cd fails.
     SC2230 # which is non-standard. Use builtin 'command -v' instead.
 )