Error Reported During Bowtie Installation

Symptom

When running the make command to perform compilation during Bowtie installation, an error occurs. The error message is "narrowing conversion of '-1' from 'int' to 'char' inside { } [-Wnarrowing]".

Key Process and Cause Analysis

An error occurs in narrowing conversion.

Conclusion and Solution

Modify the alphabet.cpp file.

Open the alphabet.cpp file. /path/to/BOWTIE indicates the Bowtie installation path. Change it as required.
vi /path/to/BOWTIE/bowtie-1.2.3/alphabet.cpp
Press i to enter the insert mode and modify about line 276:
Before the modification:
```
char mask2iupac[16] = {…} 
```
After the modification:
```
signed char mask2iupac[16] = {…}  
```
Press Esc, type :wq!, and press Enter to save the settings and exit.