macOS installation requirements missing requires brew/ports gnu-sed/gsed package

[AshKetch-um]

The retdec runtime uses sed with flags that are incompatible with the sed built into MacOS, however the Run on MacOS instructions omit this requirement.

I resolved this by installing the gsed (sudo port install gsed) package and then including the GNU symlink tree (/opt/local/libexec/gnubin) in my path before the built-in directories. A similar solution using brew's gnu-sed package should work as well.

Environment
MacOS 10.13.3
Mac Ports
changeset: 31cf35f

Steps to Reproduce
Download, Build and Install on MacOS

sudo port selfupdate
sudo port install cmake git perl5 python27 bison flex autoconf automake libtool coreutils wget doxygen upx graphviz

# See #98
export PATH=/opt/local/bin:/opt/local/sbin:/opt/local/libexec/gnubin:$PATH

git clone https://github.com/avast-tl/retdec
cd retdec
mkdir build && cd build
cmake .. -DCMAKE_INSTALLPREFIX=/opt/local/retdec
make -j6
sudo make install

Run against a simple test 32-bit Linux ELF binary

cd /opt/local/retdec/bin
bash ./retdec-decompiler.sh /tmp/test

Expected Behavior
Clean run

Running phase: emission of the target code [c] ( 0.03s )
Running phase: finalization ( 0.03s )
Running phase: cleanup ( 0.03s )

##### Done!

Observed Behavior
sed errors

Running phase: emission of the target code [c] ( 0.03s )
Running phase: finalization ( 0.03s )
Running phase: cleanup ( 0.03s )
sed: 1: "/private/tmp/test.c": undefined label 'mp/test.c'
sed: 1: "/private/tmp/test.c": undefined label 'mp/test.c'

##### Done!

user@host:/opt/local/retdec/bin:$ which sed
/usr/bin/sed

[s3rvac]

Thank you for the report. I have fixed this in commit 7b5289a. In short, I have modified our sed commands so that they work even with the version of sed on macOS, so there is no need for installing gsed.

The reason why the commands failed is that when using the -i parameter of sed on macOS, you need to specify an extension of the backup file. If you do not want to create a backup file, you have to pass the empty string. On Linux, using just -i without any extension suffices. Nevertheless, there were also some other issues with the original sed commands, so I rewrote them. Another advantage of the new version is that both sed commands are now part of a single sed command.

[AshKetch-um]

Awesome, thank you!