Pug Interpolation inside attributes?

Question

Pug

I've been digging around and haven't been able to figure out how to do it right. Since I love pug, but I have to write and php code I chose so far the simplest solution (instead of phug, which is supposedly a complete solution for pug + php) - just insert php code through |

But it is not possible to insert into attributes - they are always escaped < >

The inter-t should be like this:
p some text #{variable}
p some text !{variable} - for unescaped output

Into strings like this:
- var str = "some text ${variable }" and like #{variable} is also possible
But how to display unescaped for a string is a mystery.

The task itself is typical for php , substitute the address of the image
img.imgClassname(src=" <?php echo server_img_uri()?>") - but the characters < > are rendered through &
As soon as I didn’t pervert, it didn’t work out, I temporarily decided by inserting the html code into pug, but this is not convenient ((